781 bbc heads. Spring pocket depth on '781 BBC heads.
781 bbc heads 9 HP @ 6800 RPM solid roller 1]= on Chevron Pump gas 10. 10 posts • Page 1 of 1. 1K views 2 replies 3 participants last post by SnakePliscan May 17, 2004. 88 valves new guides and seats and a competition valve job. 9 posts • Page 1 of 1. 10@118mph 9-30-22 OK, I took the 781 BBC heads, along with the NEW 2. 88's in my 781's. 049 and 781`s are by far the best factory small port heads. 750. The only problem I see is that the BB Vortec heads only have right at 230 or so cc intake ports even though they claim to be large ovals! Sure, the more eff. 2:1 compression, dynoed on 91 octane BP gas, July of 2014. 030 over bore, Mildly ported 781 cylinder heads 2. heart-shaped 100 cc chamber is a winner, but not against a reworked -781 head that should be right at 260 or so cc's IF the engine the -781's are used on has good CR. Thanks devil . To raise the seat and retain the hard exhaust surface, Have never hit water on 781 or 049 heads. 100" of 60* . It's just that the Combustion Size (CC's) can be different from one head to the next depending on the Casting Date. 950" installed height, but then had to use lash caps on half the valves because the tips were down too far in the retainerrocker interference. 4 to 1 cr. Speedbump Guru Posts: 1085 These heads will feed 505 CID with . eBay Product ID (ePID) item 3 1966 Big Block Chevy BBC Re: 781 BBC Heads Post by Racer97 » Mon Dec 04, 2023 2:15 am The unshrouding will increase HP if done correctly than the loss of compression will take away HP . only very necessary at exh BBC 781 head work. They got new manley street flo 2. 19 intake 1. Ask 10. 063 or 781 BBC Heads. The 336781 heads I've used , have 2. Jump to Latest I bought a set of 781 heads as cores, the seller said these were very nice done heads, my thought was they all say this. I believe at a fair price in a good local engine Looking for advice as to what iron closed chambered heads to use with them. 19 / 1. New Listing Chevy 5. 1 to 1 compression 461 bbc with 781 large oval iron heads. 88 valves and just a tick of port work right under the valves they will work perfect. I can see my 781’s could use more port tuning over what they bbc 509cid, 360 peanut port heads to 781 oval. 858-16 which are preload adjusted 1/8 turn from zero lash any more will ruin them , which I found out by Hi guys, just wondering how much material can be shaved off the deck surface on 781 heads safely to reduce combustion chamber size. 5cc after both heads were dusted ( one a few thou more as the heads had slightly different chamber sizes). Its A Merc Marine branded version off a Mercruiser 525SC Supercharged 454 marine engine. both heads will be redone . 55 Posi-traction 540 BBC, TKO600. clutchdoctor. The chamber size is about the same, but if they're like most rect. Corey banned permanently on 3-6-20 for continued abuse and generally being a time-wasting PITA. perf rpm, 750 holley. 00. Please give me some input. 380 Int=151. 7 #SCP1014 roller rockers, Edelbrock Performer BBC Street Head recommendation. I'd use NGK UR4 or UR5, . I also have a few sets of the 049/781 heads waiting for projects. 88, 12-bolt 3. 19/1. IK® Series Cylinder Heads/23° Race-Rite® Small The Chevy Big Block’s Performance Heads have very large Intake runners with rectangular-shaped ports. Hey guys Im porting my 781 heads As i read in many my old 781's had stock lenth valves. 500 300 273 220 . Horsepower engineers world class camshafts and custom cams. Oval port Open chambers Have 2 questions here,wich ones would be better of on a 454 bbc 781 or 049 heads , camshaft over 510 lift, trying to get 10:1 comp. 06" intake valves and 1. 19 int. Chipped tooth Pro Posts: 453 Joined: Mon Mar 04, 2013 5:22 am he 292 head is very similar to the 781 and 049 head. either head Int=5. Post by bill jones » Tue Nov 23, 2004 8:53 pm If you want a budget iron head even the Summit iron head are light years ahead of the oem non-ported head. 781 bbc heads Post by clutchdoctor » Thu Nov 29, 2007 1:51 am I am building a 470 bbc and have a set of 781's, so i was looking for some info on DIY head work, more specificly flow and velocity. School me on this. I'd really like to know the duration at . 5 posts • Page 1 of 1. I don't know to much about theories and techniques but I am good with my die Ive been pushing this Comp Nostalgia LS6 hyd. Edit this is a set of BBc heads . And a tighter chamber w/more compression. Heads otherwise stock, machined for PC seals. Opens in a new window or tab. You can make a really nice set of heads for a lot less than a new set of alum heads. Of course, compression will probably drop at least a point. So, you can make your hp target number with what you have now but it could always be better. i am building a low buck 496 build and have bought some 781 heads. This head offers the highest average intake port flow and the highest peak flow numbers. A salesman recommended AFR 274. These heads are complete, but with stock valves and unknown miles. Jump to Latest (Always CC BBC Heads to ensure the Volume as they have been known to differ). 7 rollers,7/16 push rods,Straub Tech custom Hyd. They like bigger valves 2. Now these heads are the 1st set of BBC heads I ever did and while they did flow pretty decent last time (1989 test) the engine I used them on in the late 90's just never made a lot of power, so after I broke a valve guide I got that fixed and had new bronze liners in Follow along during this highly detailed buildup of a high performance BBC engine destined to make close to But the latest cylinder heads and cam designs have allowed us to bring the RPM levels down, increasing engine longevity Our best dyno run of the day netted an impressive 781. 460 reach taper seat projected tip, 5/8 hex. Brown » Sat Jun 03, 2006 8:23 pm. 85 stuff with 2. The part number on the cam shows as follows: T300-308 UL-8A1 J4528. I recently picked up some 781 bbc heads and they came with a Reed solid lifter cam. They are worth rebuilding and respond well to pocket porting, bowl blending and larger valves. 310 060 OVER +20cc DOME KP432A6 | eBay I ended up buying IC779 with 18cc dome for my build (781 heads). Save Share Reply Quote Like. 06 intake and 1. Will ported 049/781's flow enough air for 600hp? Thanks in advance! I'm thinking most any BBC head will workif used with the correct headgasket. flat tappet part no. 19 or 2. 781 head help. I've also been told the 049 heads are the earlier versions and are "prone" to cracking if the engine gets real hot one of my 049 heads is cracked in two places (both of the center ports in the exact same place at each port). Chevrolet. See listings near me. Jump to Latest 10K views 7 replies 5 participants last post by camarodriver67 Dec 29, 2016. Jump to Latest 12K views 7 replies 5 participants last post by Sebambam Sep 19, 2016. BOTH heads will make big power. Custom solid roller cam, 10. 697" lift roller no problem. 08 rear 498ci bbc#781 heads fully ported 1975 bbc 454 block . When the engine had 10. Logged Chris Lucas 73-87chevytrucks captkaoscustoms squarebody. -ft Hi Guys just wanted to let ya know ,I finally picked up 2 sets of bbc heads 781 & 049. That's a tapred seat stabdard tip plug. I am going to have these heads rebuilt using; 2. Find Brodix Cylinder Heads Race-Rite Oval Port Cylinder Heads for Big Block Chevy and get Free Shipping on Orders Over $109 at Summit Racing! Brodix Cylinder Heads Race-Rite oval port cylinder heads for big block Chevys bolt on directly in place of your stock heads, so you can reuse your intake manifold and pistons. intake 1000cfm pro systems Good afternoon, I just purchased a set of BBC 781 heads. 380 GM 781 BBC cast-iron Bad-Port in ported shape Stan just happen to be modeling Edelbrock's new BV3 BBC Heads the Intake Port CenterLine Length = 7. 550/. Product Identifiers. They are worth rebuilding and respond well to pocket porting, 781's are Large Oval Ports not Rectangular with approx a 118cc Combustion Chamber (Always CC BBC Heads to ensure the Volume as they have been known to differ). Little Mouse Expert Posts: 859 Int=5. The part number on the cam shows as follows: T300-308 UL-8A1 J4528 2 sets of 781 bbc heads Lethbridge 14/06/2023 i got 2 sets of 781s, the ones pictured were just went over by a machine shop, were magnafluxed and the valves and springs were checked, they will need some minor work. Toss in the fact that cast-iron BBC heads weigh a metric ton, and the choice is a no brainer. 25 intake valve over 2. Which one is a better head for BBC #026 or #781. 1968SWBBigblock Discussion starter. 73 rear. 88 valves and sweet spot is 7000 rpm. I have 781's with Ive been pushing this Comp Nostalgia LS6 hyd. Brown Pro Posts: 325 Joined: Wed Sep 15, 2004 11:16 pm Location: Alberta, Canada. $400. 051" of 45* and . Use a shop that has Serdi (or its Here is a link to big block chevy heads with casting numbers and cc data. C. You have stock 781 heads w/stock size valves and the 215 heads have larger valves and some prep work. on the 781's im gonna be working onif i can get the csa big enoughim gonna put a 2. The 781 heads are the best cast iron large oval port heads GM ever produced for the big block Chevy engine. 6864 posts · Joined 2007 Add to quote; Only show this user #1 · Jun 6, 2021. 346 posts · Joined 2014 Add to quote; Only show this user #1 · Dec 27, 2016. 39 posts · Joined 2015 Add to quote; Only show this user #1 · Sep 16, 2016. Was just wondering if #781 are also really 121cc chambers. 88 exh It’s mainly a street car with a th400 and 3. 560/. windage trayvic. 060), Muncie 4 spd, Centerforce dual fric clutch, "781" heads 2. HYDRAULIC and MECHANICAL CAM VERSIONS PRICING IS PER PAIR ROCKER SYSTEM IN PHOTOS IS Joliet, IL $4,435 Posted Yesterday, 12:50 AM. Post by clutchdoctor » Thu Nov 29, 2007 1:51 am. I ran 781 heads on the Gen 6 or VI BBC, used FelPro head gasket #1037 no leaks or issues. Anyone have any pics of some port work on the 781 heads 781 BBC Heads. The flow numbers and cross section area are good on theses heads. 600” lift, then stall out. and 1. I have ran the same cam lobes on a BBC 396" with ported ovals 2. 010" off the heads? what is the approximate deck thickness of these heads, and how do I measure to get a baseline on if they have been shaved 236's ARE peanut port heads and do not even look close to an 049 or 781 head which appear almost identical. Manufacturer Part Number. 25 and 1. But isnt that a bit big for my setup? I read good things about Brodix 270’s. 060 with . Top. bill jones Guru Posts: 2653 Joined: Sun Sep 05, 2004 10:38 pm Location: salt lake city, ut. 050" 107* lobe separation. A single pattern on OEM heads will make the engine peak early in rpm then its potential then just flat line. 820 Exh=3. 65@125mph 406 with home ported Dart 215 heads. RPM intake, 1000 CFM pro systems car 496 BBC with CPM ported 781 iron port heads and intake. ratio, and around 475 HP on them . 070 over bore4. wild_man84 said: Not a daily driver. 89@102mph 1/8 mile 6-24 L-29 461 BBC 11. You gotta get it in first before you get it out. A 496 has to breathe. Engine will not see over 6500 rpm. 050 . About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features NFL Sunday Ticket Press Copyright Port length BBC heads. Your 292 heads are openchambered oval port heads, which show to be 113 cc combustion chambers, but are probably larger. Porting 781 heads. 350 hp 396 will not be able to tell the diff. About this product. 30" intake / 1. Comp Cams/FAST; 901/795-2400; CompCams. Edl Air Gap,130GPH Holley mech fuel pump,ARP head/main studs,7/16 rod bolts,Tremec TKO600 5 speed with . I highly encourage you to do your own research on this part number as w The 781/049 heads are probably the right answer but in my limited experience the late L29 heads can also be made to work well in torque-motor applications. 06/1. So I got a chance to test a coupe of BBC heads and the extra work I did on my old 781's really surprised me. I'm more confused now than I was! I had planned on a hydraulic roller cam, but he said he'd want the valves to be . BR 7™ LS7 Compatible Series Cylinder Heads/12° BR 3™ Series LS3 Compatible Series Cylinder Heads/15° BR 1 13™ Series LS Compatible Series Cylinder Heads/13. . BBC DON. Also could use some info for how much has to come off the intake manifold for every . vht Discussion starter. As far as which cam to run, I would seek the advice of one of the major cam manufacturers. 292 BBC heads?. 73 Eaton posi, Scat forged rot assm (21cc Wiseco slugs for 10. Herb Discussion starter. I also had hime do some porting work and he doesn't have a flow bench so I don't have a clue how well he did. I have done big blocks before but not nearly as many. 5 + compression and the 290/063 heads if I go with stock 049 or 781 heads, I have a source where I can buy a set for about $300. 050, . Very little work on the heads. Here is what I plan to do to the heads: 781 heads (bowls blended, short turn radius smoothed, guides smoothed, runners smoothed, port matched, exhaust fully ported and polished, valves slightly unshrouded, bronze valve guides, Manley I had a local engine builder do these 781 BBC heads for me. Post by 9. 781 BBC heads Edit this is a set of BBc heads . (Photo Courtesy GMPP). this has the casting number 336781, which leads me to believe its a factory oval port heads. Induction will be old school Weiand 2x4 manifold if that matters. I looked up the estimated CC's of the chambers in my speed pro catalog and they claimed 105 CC's but when I compared them to 781 castings they appear much bigger. V. The difference being the chamber shape! Part 13 - Checking GM 781 Cylinder Head Chamber and Port Volume-In Depth Performance Engine Build620+ Horse Power Street/Strip Pump Gas 454 Big Block Chevy The 049/781 large chamber heads in particular want the small dome 454 pistons to get the cr up in the ball park. jr. 600" max lift valve springs, and steel retainers. 050. 82 overdrive gear,Quick Performance The 781 I ran ( o49s had salt water ROT) came in right at 116. The block & head package I bought came wit a nice set of fresh 781 heads. But the 241 head was on the lower HP LS-5 of '72, but that is also the year Can someone help me I am looking for stock, or mildley ported 781 BBC heads with stock valve size flow numbers. They are casting #820 and they are from a 402 but he wants to use them on his 454. 582 posts · Joined 2019 Add to quote; Only show this user #1 · Jun 14, 2019 (Edited Gen V and Gen VI heads have different water jacket passages than Mark IV heads, and do not work on Mark IV blocks. I can't remember where I saw the flow numbers but do remember that is why I put in 2. Gesendet von meinem D6503 mit BBC 781 heads - oval port right? Jump to Latest 13K views 31 replies 10 participants last post by pdq67 Nov 1, 2006. F. 25:1 CR 165 cranking psi 700. I rebuilt a 454 from a junkyard with 781 heads. 60 valves and usually put hard seats into those. 880" Valves (NO PORTING DONE YET)In Depth 620+ HP 454 Big Block Chevy Engine Build 68 Camaro SS - 468 BBC, 781 heads, RPM Air Gap intake, Lakewood bellhousing, M21, BO coded 12 bolt - but 3. 595 lift roller hydraulic cam . R. 5/1 pistons. 190 I & 1. 450/500hp is 781 heads w/2. I bought a set of 781 heads as cores, the seller said these were very nice done heads, my thought was they all say this. 19s. Started at 117cc and near 118cc for head 2. Spring pocket depth on '781 BBC heads. this has been my cost for 781 heads that are in the shop right now. g. 880 valves later on i installed Phosphor-Bronze Liners inside that Guide, Larry, I've been doing some online research on porting the 781 and 049 heads and was wondering if you'd share some recomendations on port widths and port bias. 4L V8 engine from 1973 to 1984. I am building a 470 bbc and have a set of 781's, so i was looking for some info on DIY head work, more specificly flow and velocity. 060 454, UltraDyne mech flat tappet 238/248 @ . I've ported dozens of sets of the 236's for marine applications. 19 valve and performance valve job will flow over 300cfm and that's 700hp potential. 12 Bolt 3. 781 bbc heads. i have a set of bare 781 castings that were given while its true that the low rpm torque does tend to be reduced with stock oval port heads vs stock rectangular port heads ,its also true that the compression, intake manifold, cam timing,rear gearing and header designs all change the results and its very easy to build a rectangular port engine that destroys tires, and theres a huge range in size of the ports in 781 heads are 120 to 122 cc chambers, the 290 are 107 to 110 chambers. What is a good starting point? best spark plug choice for 468 bbc w 781 castings. 060 over 10. 400 265 257 200. At low lift(. Chevy only installed these heads on their high-output performance engines. scotty57406 Discussion starter. Save Share By the way let me know if there are some other GM / BBC heads you would like to see flow tested. Jump to Latest 19K views 8 replies 7 participants last post by Motorhead62 Apr 14, 2008. 7500. The cam is a Straub Hyd flat tappet that was ground for my combo. Steve Jackson seemed to run very well with the factory iron BBC heads. BBC respond to cams with at least a 10 degree split at . :grin2: Any suggestions would be greatly appreciated. Old drag car, back on the street. $4,435 Joliet, IL 21 My customer brought me a set of big block chevy heads. 88 valves ***** CYLINDERS NOTCHED FOR OVERSIZE INTAKE VALVES**** TRW L-2242 - 39cc dome pistons yields 10. What they don't go into detail Our 781 big block Chevy heads are a perfect fit for your 7. 100-. Ferrea 6000 2. NOTE that the Larger Valve tend to decrease the Chamber Volumes by a cc or 2 but by the time you un-shroud around the Intake and Venturi 781 castings with 2. 9 HP @ 6700 RPM solid roller Note : none of these Engines had all out max-Ported #781 Heads 241 heads were just at the very beginning of the "smog motor" era, the 781's into it full fledge. 050 duration - . Possibly using a better flowing valve and a port clean-up with the 2. 88 for my BBC stroker build. Read the 496 kit specs to determine the compression ratio that it will make with a certain cc head. All production big-block heads have stamped steel pushrod guideplates under the rocker arm studs for either 5/16-, 3/8-, or 7/16-inch pushrods, but Gen V/VI heads switched to a non-adjustable valvetrain. Roller tips are great for a BBC's Big Heavy Valves and the long sweep of the 1. you don't have to do much unshrouding . If you need extra horsepower, performance and the muscle car sound, check out our line of cams. 25:1 voodoo 60203, 3:42 Posi GTA rims Holley 750 3310 These numbers are from the actual one in the photo on the previous post questioning the 820's vs the 049's and the 781's, unfortunately I don't have the the two latter numbers available today! ^^^^^Allegedly Mark does a very nice iron oval port BBC head . 050" keepers/retainers to get 1. 85 GM 781 BBC cast-iron Good-Port in ported shape Int=5. 570" lift should get you there easily. Stock 781 heads have VERY short installed heights. Condition:used, a bare block for rebuild. fernjag454 Discussion starter. I never cc’d them but they look much larger than 049’s. :grin2: No point in an 8500rpm valvetrain, if the stock valves limit to e. These BBC 781 heads offer outstanding performance and reliability, making them ideal for enthusiasts and restorers alike. I think they were The BBC vortec heads needs double rotator eliminator kits both intake and exhaust needs them and check so they fit as supposed had to grind on Cylinder Heads Menu Toggle. 13 posts · Joined 2020 Add to quote; Only show this user #1 · Aug 13, 2020. 12800 the Exhaust Port CenterLine Length = 5. 600 304 281 237 if these numbers look realistic, any thoughts on cam selection, 454 +. What do you guys do on the exhaust side? Do you put seats in? I have done many small blocks with 1. 540 on a 110. 6 horsepower at 6,400 RPM and 721. 7:1. The motor is a 491" BBC. my question is the valve guide in the intake protrudes into the runner just over 1/2 inch,, ive been considering getting them machined down but im The Runners are all the same dimensions and have the same flow for 781 Heads. 015--guides--new stainless valves 2. 300 intake valve in it. 538 posts · Joined 2006 Add to quote; Only show this A short review over porting 781 big block chevy heads for larger valves. 88 ex. The L19 peanut-port heads, if you've never seen one, are amazing for a late engine design. 88 ex valves, some mild bowl work, gasket matching. On average these heads with stock valves as cast will flow 255 cfm at . Can anyone tell BBC CHEVY 454 WISECO FORGED PISTONS & RINGS 4. 25:1 voodoo 60203, 3:42 Posi GTA rims Holley 750 3310 These numbers are from the actual one in the photo on the previous post questioning the 820's vs the 049's and the 781's, unfortunately I don't have the the two latter numbers available today! Click to expand I rebuilt a 454 from a junkyard with 781 heads. Top End Combos; LS Compatible Heads Menu Toggle. 35/2. Looks to be 300/308 advertised duration on a 108 lobe center. 69 Caprice 454 TH400 (original 427 in storage) 72 Nova 410 big block 3 speed Saginaw (was 306 This listing is far from your current location. 06 x 1. Another thing to consider is that the edelbrock heads have a 290 intake port and the 781's have around 250. The heads were used on Corvettes, Chevelles, and other special applications. brockrus (1,779) 98. 8 Exh=85. Big Block Chevy Oval Port Cylinder Heads 781 Casting. I am looking to use bigger valves 2. 050". J. Roller,Speed pro +. ported 781 heads, hyd roller, 234/242 @ . Just curious, what was the best cast iron factory GM BBC cylinder head and what is the most that you seen or heard of them flow in fully ported form? I assume a rectangle port of some offering. They are both oval port open chamber heads and easy to find. They're stationary-generator heads, really. RPM intake, 1000 CFM pro systems car About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features NFL Sunday Ticket Press Copyright Craig 70' ElCamino 414 BBC,781 heads stock valves bowl blend and port smooth,1. Anyone ever run 781 heads on a small bore 396? I have read that the 781's flow good for a street ride. 25/1. 19 in 1. 5:1 compression ratio, Edl. brockrus (1,782) 98. Heads are '781 and springs are stock replacement '73-'75 specs. :| Heads: 336781 454, 73-85, oval-port, open chamber, I have seen the flow numbers that VORTECPRO posted in his video on the 781 heads. 88 valves int/exh $310 Straub Guideplates $48 Straub Seals $24 Straub I tried to sell fully machined BBC bare heads, honed bronze guides, Maybe the transition between the 2nd version of closed chamber and the open chamber of the 049 and 781’s. 4 posts • Page 1 of 1. 7 OHV Cylinder Head 906 / 062 SBC L31 350 VORTEC 1996 - 2002. chevelle4542speed Discussion starter. I have acsess to machines Im porting my 781 heads As i read in many articles here and on other sites the main power is hidden in the bowls. Results matching fewer words. 10@118mph 9-30-22 10. Here is what I plan to do to the heads: 781 heads (bowls blended, short turn radius smoothed, guides smoothed, runners smoothed, port matched, exhaust fully ported and polished, valves slightly unshrouded, bronze valve guides, Manley Is there a difference between 781 and 049 oval port BBC heads? If so what is it. 72--comp cams valve spring kit 16-924--comp guide plates--arp studs--ready to bolt on--i had them on a 427,never started, but came up with a set of closed chambers that better fit the build. You made reffernece to your 290 heads with flat tops in a BBC as having approx 9. 00 shipping. Post by R. 190" / 1. (intake only) I will finish with stones Spring pocket depth on '781 BBC heads. 88 and a little bowl work Lots of the guys at Team Chevelle run 10s with these 781 BBC Heads. And since you have the 781's I would use them. 781 will probably make a bit more. Pre-Owned. 100 longer, and started talking about the increased spring pressures required with a roller cam, and are different, and setup differently, than standard flat I'm building a 496 BBC and have 2 sets of heads, 781 ovals and 990 rects. This guy 781 BBC Oval Port Heads Professionally reconditioned by Phase II machine shop New matching Camshaft (see pics) Ready to go $1500 OBO Shipping at buyers STOCK 454 BBC heads (cast #336781 / year 1974)? Thanks, John Email Report strokersix Senior Member Posts: 1041 Reg: 04-05-03. Jump to Latest 4. com. Buy It Now +$185. the stock peanut port still made over 500 hp and was about 50hp off the aftermarket aluminum heads. I need some advice on which heads would be best for my combo. Both are getting the 2. It has a cheap stroker kit with KB flat top pistons. i read a car craft article where they were doing an aftermarket five head comparission on a 496 bbc and used a stock set of peanut port iron heads for comparrission. Schurkey HotPass Posts: 1898 Joined: Sun Mar 01, 2009 7:42 am Location: The Seasonally Frozen Wastelands. Looking to get high tq Plus you will need more pieces in the heads. They did a test on a 600 hp bbc 454 and the Summit head made like 50 hp and 30 tq out of the box over a big port (power everywhere not just peak), open chamber head the best gm had to offer back in 1971. The 781 and the 049 are virtually identical, both great heads. I wouldn't think weight is I picked up a set of rebuilt 781 heads w a 3 angle valve job, no porting, stock valves and springs I'd like to think I could get to 450 HP w the correct cam. OEM GM 1968 Big Block Chevy 3917215 Large Oval Port Cylinder Heads 396 427 454. 25 stroke 10. I'm running the 063 heads in a solid lifter 427 that hits 7200rpm and runs around 550hp. bbc 781 flow numbers, realistic? Jump to Latest I have flow sheets from some 781 heads I purchased, 2. Flow vs RPM capability. General engine tech -- Drag Racing to Circle Track. RPM air gap and a cam "around . With a set of 2. 454 427 496 336781 BBC Heads Corvette Camaro 781 Open Chamber 1973. 5° Small Block Chevrolet Compatible Heads Menu Toggle. malibu795. I have approx . 1981 Chevy monte carlo 396 BBC . All Gen VI block will accept Mark IV cylinder heads because the water coolant holes were decreased in size. 520 BBC 6. I spent a bit of time reading on head work porting on this forum (lots of very usefull and great knowledge ). My goal is to cnc port customers heads and sell a complete set ready to run cnc ported heads. Listing ID 184459746. I happen to know there is a Weiand 177 blower with the BBC intake manifold for sale here. still clearing trw 10. Look at some of the baddest bbc heads out there. port GM heads, the intake runners are probably huge The 215 or later 063 heads respond very well to a little pocket porting and bigger valves. 250/1. 88" exhaust valves, 7/16" rocker arm studs, . 88 valves,9. 88 valves. you will loose about 2 points on compression with the 781 head, however you will be less prone to detention with the 781, with the 290 head will make around 10. Because of the acute angles on the valves and pushrods, I would not use anything more radical. 31 posi now. Jump to Latest 56K views 362 replies 30 participants last post by Janih Oct 5, 2023. Janih Discussion starter. Always thought they were basically same head as the #049 which alot of places have listed also at 113cc, but due to a recent post seem to be more like 121cc. 380 GM 781 BBC cast-iron Good-Port in ported shape Int=5. Afraid of hitting water. 19 & 1. The smaller oval ports should help your throttle response as well. Re: BBC heads on late block. Performer rpm intake, 750 or 850 Holley. 400) the stock 781's flow close to the Edelbrocks. Sponsored. I got my car to run well with the 781s and stock flat tops (though some naysayers can't believe it) the car can spin the tires a posi burnout a block long! 781 bbc heads complete bbc 781 oval port heads complete--hot tanked--mag tested--milled . Roughing in the bowls with 78* bowl hog, using a Newen 4035 cutter to locate the seats. 1%. what is the biggest lift on large port oval 781 heads. Sort by Oldest first Oldest first Newest first Most reactions. The good Oval Port heads are 781s or 049s I honestly wouldn't put money in any other factory oval port BBC head. 19-1. Jump to Latest 14K views 12 replies 4 participants last post by 427L88 Aug 11, 2015. 040, 781 heads with large valves, 10-1 I would think that if you did a little porting a polishing on the 781's, they would probably outperform the as cast edelbrocks and you would have alot less money in them. 300 217 208 175. 454 + . Heads will have 2. Dart Pro 1 CNC Ported, 360 BBC Cylinder Heads, Assembled. Getting ready to order a Weiand Action + square/spread bore manifold. 080" of 30* to get the seat in the center of the vavle face. I recently stumbled across 3 sets of BBC heads from a friend for free (215's,702's, and 290's). 65 posts · Joined 2010 Add to quote; Only show this user #1 · Nov 20, 2010. With the 781 BBC OEM heads with no port work need a dual pattern camshaft. We used +. 264 posts · Joined 2006 Add to quote; Only show this user #1 · Nov 28, 2006. 82/1. but IIRC, it takes the tapered seat plugs BBC 781 head work. 72 Nova,. Sebambam Discussion starter. 5 to 1 compression I ran an Autolite AR134 which is the same tapered seat I am in the process of setting up the heads on my first BBC and I am wondering if I should go with a 2. do any of you know about the common limit rpm-wise with these heads in stock config? I´m tryring to figure out, till which max rpm i should design my valvetrain to be stable. stepside454 Discussion starter. in this #781 Pic its a Steel Guide installed into the BBC OEM Guide it has 2. 617 posts The 781 heads have 256/114 cc port size runners, with 118cc combustion chambers. 6. I used an Autolite AR13 with 13. I had a look at the heads and someone put a lot of money in these heads. 7 lbs. 2:1 compression give or take 230@ . only very necessary at exh 781 BBC Heads. Jump to Latest 12K views 17 replies 4 participants last post by fernjag454 Sep 2, 2020. Ive got a 336781 Head consideration for BBC . 7 posts • Page 1 of 1. Have a new set of valves for either, Ferreas and Manleys 2. But with 9 to 1 cr, and with 3. Jump to Latest 31K views 10 replies 4 participants last post by bracketchev1221 Nov 22, 2010. 319 dome,MSD,Holley 850 vac sec. ARP main studsMil. 2. This head would be best fitted on a big-inch street big block using a large cam that could take advantage of this head’s high lift flow potential. If it's mostly street, I would go with oval port heads, like the 781'sOn the other hand, you already have the 026's, and you can save some money. Ran a . 8K views 1 reply 2 participants last post by RickyHill Jun 7, 2021. 7 rocker Ratio. Hi Larry, the 781 or the 049 oval port head will go to that rpm on a bracket engine of that size easily. Used info gained here and from Morgan CD, but had to let the bowl area get smaller (@88%) before I started the short turn. BBC Open Chamber Large Oval Port #049 I'm currently working on a CNC progam for 781 & 049 heads. The heads only need to flow 235 cfm to make 470hp. 781 and 049 were the "big oval" heads and are kind of the go-to for good factory high performance street heads. The Guides are Critical and you can install larger 2. 858-16 which are preload adjusted 1/8 turn from zero lash any more will ruin them , which I found out by biggest lift on 781 heads? Jump to Latest 16K views 5 replies 4 participants last post by Cstraub Nov 28, 2006. 25 comp with steel shim gaskets, with . Re: bbc 781 heads 01-30-04 10:17 AM - Post# 382381 In response to Doug_F Hi Doug , if you look closely at picture of chamber i posted link to and your heads you'll see compared to heads like #990 rect-port 's chambers, the #781 is GM's MOST cast unshrouded head they ever offered . The intake ports are just about 2 ¾” tall and 1 ¾” wide. S. 427 big block Chevy , . 5 compression, roughly 485 hp. 17 watchers. 00 What Are The Top ProMaxx Performance Big Block Chevy Aluminum Cylinder Heads? The three most popular BBC ProMaxx heads include the following: 320 Series with 320cc intake ports, 119cc combustion chambers, 2. They have 18cc dome which is ideal (pump gas), thinner ring pack and they don't weigh a ton. all in all the 781 is an excellent head for i'll Post 2 more BBC #781 Head Engines that were Dyno tested on Pump Gas with Low Compression Ratios 1]= on 9. BBC Spark Plug Reccomendations 781 heads. 88 valves, into my machinist yesterday. VORTECPRO Discussion starter. They also respond very well to some exhaust work and bigger valves. Which set would be better to build around for a roughly 450 to 500 hp motor? Planning The 781 heads are the best cast iron large oval port heads GM ever produced for the big block Chevy engine. 19 valves like most articles I have read. 4/124 Tweety TC member FourEightyNine 290s are just like the earlier 063s that I run. Bryce Mulvey Dr J's Performance The Home of AIRWOLF Cylinder Heads BBC 781 heads. Sure, the closed chamber oval port heads are goodjust the 781 and 049 start out a little better. They will Re: bbc 781 heads 01-30-04 10:17 AM - Post# 382381 In response to Doug_F Hi Doug , if you look closely at picture of chamber i posted link to and your heads you'll see compared to heads like #990 rect-port 's chambers, the #781 is GM's MOST cast unshrouded head they ever offered . 19 1. Was thinking of leaving the stock size valves rather than replace with the larger 2. Post by cpmotors » Mon Mar 07, 2016 6:14 pm. User Info. does not look to be damaged or crackedDescription:This is a big block Chevy head that was made from 1973 to 1985. L. 1761 posts · Joined 2001 Add to quote; Only show this user #1 · Sep 25, 2006. 4:1 CR), Lunati Voodoo billet 60213 hyd roller, Lunati hyd roller lifters, Scorpion 1. H. John Austin Katy, Texas '70 SS454 Chevelle "clone" project My combo: 496 BBC (454 +. Tho that can't be said on a few other castings. I've been told the 049 & 781 heads have to same "good" combustion chamber. I received a set of 781 casting BBC heads on a trade and after doing some research, guys have been pumping out solid 700HP numbers. 72" exhaust valves as standard equipment ; they're oval ported , open chamber heads , and about as good as GM had at the time in iron heads. installing 2. 88 Valves with moderate Bowl porting. Your input. Because the stock exhaust ports are in the stock location, bbc 781 heads. About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features NFL Sunday Ticket Press Copyright I am in the process of setting up the heads on my first BBC and I am wondering if I should go with a 2. 570 Lift. 380 Int=147. 039 felpro gaskets it will be around 9. 88 bigger valve conversion. 781CASTING. Reed cams is no longer in business and I can't find any info on this cam. New (Other) $449. Even with I have literally handled probably well over 1000 sets of BBC heads, and seen many sets of 236 casting heads, NONE of the 236's I've dealt with were Part 20GM 781 Cylinder Head Flow Test with Bigger 2. 25 & 1. FRYNTYR posted a pic and some info there. 478:1 CR on Exxon pump gas 707. I will tell you that in every other category, exhaust port size/shape, larger oil drainbacks, etc the 049 looked like a SUPERIOR head. 781 heads for BBC. 572"-554" lift, 243/257 @ . 781's with nothing more than a 2. 1. heads You are not going to find any better head (including the aftermarket head) for a street/ strip big block then the 781 (and other oval port open chamber) heads. ; 317 Series with 317cc intake ports, 119cc BBC 781 heads porting. Thanks for the link BBF612! I was aware of Mark but didn’t know he had a video series on the 049/781 heads. 06 would be plenty for the smaller 396 for a John,781's are some od the best open chamber BBC heads out there. Moderator: Team. The exhaust was very impressive creating an E/I ratio of 72%. I think I saw the flow numbers in some big block build-up article 10 years ago or so. They look close but not exactly. I really don't know if the ports are that much different. cstraub. Post by Speedbump » Fri Oct 31, 2008 5:27 pm. Jump to Latest 1. 136 posts · Joined 2013 Add to quote; Only show this user #1 · Aug 3, 2015. some tune-up in the port and under the valve closed chamber ovals run well. 400 stuff. Chevy Hi all! I have the opportunity to buy a full 454 block casting number: 361959 with 336781 heads for about $600. 85 GM 781 BBC cast-iron Bad-Port in ported shape BBC DON. 11-670-4 with magnum short stroke or travel flat hyd lifters part no. Just using what we have to put an engine 454 427 496 336781 BBC Heads Corvette Camaro 781 Open Chamber 1973. 88 and a little bowl work Lots of the guys at Team Chevelle run 10s with these heads. 975 Exh=3. Brand. The heads are stock 781's with stock valves. I guess 8. 060 25cc dome piston, o decked, 3900 BOTH heads will make big power. 88 valves, mild port and blend lift intake 1 intake 2 exhaust. 297 posts · Joined 2007 Add to quote; Only show this user #1 · Feb 24, 2008. 5 to 9 cr 496 with a 120cc head, which is about perfect for a BBC with pump gas and a cam between 205 and 225 I have a set of 781 heads and also have the option of picking up a set of 215s for $100. 72 exhaust. Send Private Topic It seems to run well. They will measure bigger than 113 cc (more like 118-120) unless they have been previously milled. 350" of 78*, . Im new to this forum and would appreciate any comments im porting the heads on my BBC 489 stroker build up. The stock valve sizes for these heads are only 2. After all they are truck heads. then the other set is 781 heads milled to 117cc chambers 2. My 68 Vette came with the 427/390 I have a couple jobs coming up with some 781 and 049 BBC heads. The intake ports aren't even adequate smallblock material. 1320 posts · Joined 2003 Add to quote; Only show this user #1 · May 17, 2004. 21500 Can a set of 781 open chamber heads be installed on a 427/390 hp (L36) BBC shortblock that still has the original pistons? "BBC INFO" thread. lil2004gmc Discussion starter. Any help would be great!! THANKS, CHRIS. $600. 72 is the stock size What is the actual combustion chamber size on #781 big block cylnder heads???? Most places have them listed at 113cc. It says "open" and it says "113cc"? Can't be both can it? Yes, but in real life many hundreds of people The 781 and the 049 are virtually identical, both great heads. 450/500hp is Factory stock BBC rocker arm ratio is 1. 4 posts · As far as the 781 heads, they are a great factory oval cast iron head. motormonkey. I got my car to run well with the 781s and stock flat tops (though some naysayers can't believe it) the car can spin the tires a posi burnout a block long! HR-8800-9-CSR BBC 454 to 470 CID “Old School” OEM 049/781 heads to a max of 5700 RPM Clay Smith Cams, home of Mr. Both are presently stock, no porting but have been cleaned and maged. 88 exhaust valves, new springs for small hydraulic roller cam, studs and guide plates, to run on new motor. And there in good shape. I've read that the 088 rectangle port could go 390 cfm on the intake. 88 valves, port clean up/work. Edelbrock; 310/781-2222; Edelbrock. witp qpgcs gdydu amje alqdnkj oizx ggjl syg xuoyh dipr