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After market BBC Heads

12K views 23 replies 11 participants last post by  clifford1985 
#1 ·
For an 81 454 dually, I got my hands on a Holley Avenger EFI setup that mates to rectangle port heads. I unfortunately have oval port heads and need to source some that I can use. Somebody school me please, I have never replaced heads before. Open vs. closed chamber? The p.o. claims 'roller motor'. If I want to kept the valve train as it is, I have to consider valve and seat diameters, pushrod lengths, etc. What am I in to here? Advice?
 
#2 ·
Get the Oval intake for the EFI. Rectangular ports are not going to be any good in a 454 unless your in the very high RPM's, or your way bigger than a 454 like 540+ CI.

BUT you prob have the peanut port if the its a stock 81'. I would look for a set of pre-75' heads those are the "large oval's".

We can get into how you should build your motor too. But it all depends on how much you want to spend and how much power you want.

I would get a set of pre 75' open chamber heads with a bigger piston. In the 9.0-9.5 CR range. Then get a cam to match.
 
#3 ·
oval pretty much kill a BBC by 4500 world product as a good set of aftermarket bolt on iron ovals that will imporve range upto 6000-6500
stock 049 and 782 heads are the large ovals and usually need at leas a 2.19/1.88 valve upgrade from the 2.065/1.75 that is stock.

400hp is relatively easy with 9-9.5:1 cr mild cam exhaust and intake

this is rw power with a 208/214*@.050 .475/500 flat tappet camshaft 049 heads with 2.06/1.88 valves
performer intake, 9:1 cr, long tube headers, 600cfm carb. and msd ignition
 
#4 ·
Thanks y'all I really appreciate it. I think I will try and find some large ovals; I was surprised to find they do in fact make the same setup for oval ports. It doesn't specify whether the intake is for large oval or peanut though. I am not looking to build the motor.

Yes, from what information I could gather, rectangle ports do make more horsepower, but only with a substantial amount of valve lift, a good meticulous port job and in the much higher rpm range. The truck does have an aftermarket cam, but I don't know lift or duration. :shaking: I believe it is a solid roller valve train, but I am not around it right now to do any investigating. So, with a recent rebuild, mild, street mannered mods, and my experience level, I'll just have to swap for the oval port intake. That being said, I imagine that Holley did not make this intake for weak sauce peanuts so Just gotta find some heads. My guess is, the stock heads are open chamber?
 
#6 ·
Thank you all so much for the information you provided, it was very helpful. My foolishness in buying the wrong part has landed me in a bind though. I am not able to return the EFI setup as it was a special order and is past return time as well. The way I see it, I can spend another $450-ish on a replacement oval port intake and attempt to sell this one, then buy heads, or just get some rec port irons. Given my predicament it makes more financial sense to me to just go with the latter. Although rec's aren't the best option out there, I have to imagine they are still a step up from what I have now... Correct me if I am wrong. At the very least, no worse. I do not want to spend $193746976 on aftermarkets either but it's that or search for a used set that can pass inspection and is appropriate to my application. I will figure it out; y'all have definitely shown me were to start looking.
 
#7 ·
keep the intake, put it on the oval port heads.

some racers used to do this to gain more mid range, and it seems to have worked. what you are trying to keep from having is a restriction in the intake airflow. the heads will still pull what they need.
 
#10 ·
What is the BEST option in heads, for right around 500 bucks? The 049's with a little work? I have a set of peanut heads, but they have bent valves, and my bottom end is coming fresh from the machine shop, so I don't want to waste time/ money redoing the the peanut port heads. But I don't want to dump 1000 bucks on a set of heads either.
 
#13 · (Edited)
781s are pretty easy to find..Ive had them on a 468 on pump gas make 500 hp easy..Thats in street trim with a Q jet.
On the average set of old school heads you will need to get them Magnifluxed, Hardened valve seats installed if they haven't been done,The guides checked and replaced if need be,a valve job due to the new seats, and then you need new valves..Talk to your machine shop about the cost of all this work before you plunk down a few hundred bucks for a set of used factory castings..The aftermarket or even used aftermarket heads could be a better choice.

Grumpy seems to like the race rites but dont overlook a used set of Brodix BB2's or BB3's and the BB2/3 extras.. You can sometimes find them in good shape used when a rail car owner wants to run faster..Many Brodix guys have went to Profiler and the like.

Most all aftermarket heads will have the hardened seats for unleaded fuel, good bronze valveguides factory installed.So freshning them up with new matching springs to your cam,seals, andwhatnot can be cheap if you look around.

The good thing about BBC stuff is that with the influx of guys wanting LS engines to run in street cars the BBC stuff isnt gold like it used to be..Before the LS i used to see guys get into fist fights over stock 80s big blocks that cost 1200 bucks:shaking:Now its not so bad, at least in my area of the country.
 
#21 · (Edited)
With todays fuel and additives in the unleaded fuel one would be stupid to run non hard seats in a street application, especially in a dually truck setup.Now burning unleaded fuel with soft seats wont kill the seat face super fast but add the loads of towing and the issues of running lean enough to pass a sniffer..Its not worth the savings just to keep the wallet fatter..But i guess he could just fatten it all up loose power and foul plugs..:shaking::flipoff2:

Seat pressure while is is important( OP does state its a full roller engine),has less merit for the need of upgrading the seats in a street engine that will see long heavy loads hauling or towing..The OP has this engine in an 81 dually, not a SWB C10
 
#16 ·
Assuming that your 454 is the original block from 1981. Your dually is the Mark IV Generation Block, hydraulic flat tappet cam, 2 or 4 Bolt, with low compression Peanut Port cylinder heads, not Oval ports. The truck series originally came with peanut ports, for towing. The way to determine that is with the head casting #'s but also very noticeable just looking at the intake runners. Peanut ports are the worst cylinder head in terms of performance and flow. If your looking for performance the first thing that should be ditched are those peanut ports but compression & choosing the right piston is everything also. If you can find a stock set of true Oval ports, that would be a great upgrade, and not that costly compared to after market, but that depends. On one of my big block build ups, I went with a domed power forged piston along with a bare set, Cast Series D port exhaust, 269cc/119cc World Products Oval Port Merlins, and custom built them from there with pocket porting, stainless valves 2.19/1.88, with the correct valve spring specs based from your cam specs,etc. Get ready to spend money, that's all I can say, if you really want a Bad Ass to the bone Big Block.
 
#17 ·
There are cheaper heads out there too. You dont have to go with the big names to get a head that will outperform any of the stockers. Check out RHS heads. Good product and affordable. Summit and Jegs even have iron heads that they sell as a "house brand". Might be worth a look. Your machine shop may be able to help you out on the cost too if you are in good with them. They can buy at wholesale prices that are way cheaper than mail order.
 
#18 ·
I wouldnt consider a house brand cylinder head. Why>? who makes them? who knows...

kinda like edelbrocks stuff... i wont buy it, either, based on marketing issues...

You dont see Summit Brand heads making a lot of friends in winners circles....
but you see Dart, AFR, Profiler, and a few others.

of course, we arent racing, so any generic garbage would do, right?
 
#20 ·
OKMudn; said:
So you can take your grumpy old ass and stfu.
Seems to me that I would prefer quality over garbage.. I dont think thats too much to ask. Stock GM heads would probably perform better than some generic garbage...

What technical merit do you have to offer besides "Look at RHS and generic heads"?
 
#23 · (Edited)
Ya I have a set of Pro-Comp heads. I found out afterward what they are. The guy I used to build my motor insisted on them saying there was no complaints and that there totally fine and a good product. I found out late what a POS that company really is. And all the horror stories tied up with the SBC heads that Pro-comp makes. But you can get a set of BBC head for half the cost of the Edelbrock performer RPM heads, that they copied.

Its worth spending a little more on the heads. I just wish someone told me that when I was building my motor.:(

Edit; BTW the Pro-comp head weights ~5-7 pounds less than the eddi head.
 
#24 ·
Y'all are funny.

For those interested, I have narrowed it down a little, studying the books I have and googlin the shit out of part and casting numbers for a while.

The thing that bothers me the most is trying to research in Afghanistan while the truck sits elsewhere. I don't know if the roller combo is hydraulic or solid.

These claim to be assembled with Hydraulic roller in mind
I like the valve diameters on these as well
http://www.summitracing.com/parts/WRL-030040-2/
There is a set for solid roller on World's site, but not summit

I am guessing these are best fit to a solid roller, but I only assume that because of the max valve lift being .700? Otherwise they look to be very similar to the Merlins.
http://www.summitracing.com/parts/TFS-41300001/


Of course one way to know what cam setup I have for sure is to do a top end kits like this one. It's nice because you are paying for confidence and convenience. On the other hand, Whoa.. It's a lot.
http://www.summitracing.com/parts/TFS-K413-580-560/

These just seem very well manufactured with airflow in mind. Intake seems to be a little on the small side at 265cc and the chamber is only 112cc. But my peanuts should've had a chamber volume about 113cc, I think the current pistons should work.
http://www.summitracing.com/parts/AFR-3610-1/
 
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