[jam1719]

I new to the board and big block chevys. I have a 454 bored .040 over. The cam is an elgin prostock with a .501int and 527 exh. 214 @50 224@50. the pistons are flat top 2377 forged trws. I have two sets of heads. I have a set of 781 and a set of peanut port 360. Which head will perform better with this cam. I believe the compression should around 8.1. any help will be appreciated. thanks

[Blazin72]

Let me guess, the page wasn't responding so you kept hitting the submit post button? ha ha ha

[F-BIRD'88]

Find a set of old 1966/1968 396/325-350hpHP 96cc oval port heads. Mill about .050" off them to get 90cc. Use a factory OEM 1970Chevelle "454-450hp LS-6" head gasket (.022") (GM dealer) Your L2377 pistons should be .022" down the bore at TDC unless the block has been decked. Your cr will be 10:1

Now you can cam it up and get some power.

Here are your casting numbers 3872702 3904390 3856206

Althou not as nice at the open chambered oval ports (781-049) these early closed chambered heads respond very well to general porting and larger valves.
You should be able to sell off your heads or trade for , to finance buying these small chambered 396 castings.

Can ya tell I've been down this road before?

The other solutuon is to swap the pistons out for L2465 with a 24cc dome.

Or supercharge it.

[66GMC]

Hi, and welcome to the board.
Looks like you may have had your newbie initiation - a couple of times.

Anyway ... to answer your question (with my opinion):
The 781 heads will flow much better than the peanut-port ones, especially at higher RPM's so they are the obvious choice fom a performance standpoint.

The only time that the peanut-port ones might be a better choice would be in an applicaton where you needed ALL of the torque in the lower RPM range.

454 truck engine pulling a goose-neck RV through the mountains kind of thing.

It is also common to install larger valves as well as having the heads ported in order to make them really breathe.

Here is a link to aChevy High Performance Magazine article that talks about the flow characteristics of 049 / 781 heads vs rectangular-port heads. Peanut-port heads even get a brief mention as well.

HTH,
Don

[DaSouthWon]

The peanut port heads arent much good for much other than a truck motor. They are designed for torque. If you are looking for more revs and horsepower I would go with the 781's. These along with the 049 heads are probably the best old iron GM heads they ever put out. I would suggest if your looking for a street car motor use the 781's. One thing to consider on these heads is the valve guides sometimes need to be machined down if using a high lift cam. Another thing about the 781's, the combustion chambers are rather large, around 118cc depending on who you ask. With a .040 head gasket and standard compression height you need somewhere, around, I believe a 22cc dome to get you to 10:1. You may consider going with a different piston if your looking to make some decent power.

[DaSouthWon]

and veryone responded with just about the same answer

[Sparx74]

Originally Posted by F-BIRD'88

Find a set of old 1966/1968 396/325-350hpHP 96cc oval port heads. Mill about .050" off them to get 90cc. Use a factory OEM 1970Chevelle "454-450hp LS-6" head gasket (.022") (GM dealer) Your L2377 pistons should be .022" down the bore at TDC unless the block has been decked. Your cr will be 10:1

Now you can cam it up and get some power.

Here are your casting numbers 3872702 3904390 3856206

Althou not as nice at the open chambered oval ports (781-049) these early closed chambered heads respond very well to general porting and larger valves.
You should be able to sell off your heads or trade for , to finance buying these small chambered 396 castings.

a buddy build a 454 in the late 80s for his drag car / bracket car with 1966 396 heads on a budget big block 454 and run 13.1 CR that ole 64 wagon run 10.99s in the 1/4mi. they would prob make a good street thumper at 10.1CR in a 454 also. 781s and 049s are a good GM Casting with more CR & a cam. I have a fresh set of 049s wating for a BBC build.

[66GMC]

Originally Posted by F-BIRD'88

...
Or supercharge it.

Abso-freakin-lutely!

Those Powerforged TRW slugs you have ae a nice start in that direction.
I built my 454 with that "blower upgrade path" in mind as well.

Here's another good article on that subject.

620 HP / TQ out of an underdriven blower is just amazing.

[jam1719]

I have a 454 bored .040 over ( trw 2377 flat tops). I'm using an Elgin Pro Stock cam 214/228 @ .050. Lift is .501/.521 280adv 290 adv. I have two sets of head 781 and a set of 360 peanut ports. Which will be the better choice for this engine. I'm not looking for high rpm power just good low to midrange stop light to stoplight power for my monte carlo. Any pointer?

[jam1719]

Thanks for all the advise. Has anyone used they Elgin Prostock cams? I will use the 781 castings based on the helpful post. Just want a good strong street motor that can light the tires up.

[babygene41042]

Jam1719 use the 781's.They are almost as good as the 049's and will support 500 horse with larger valves.The cam seems a little small even with 8:1 compression.I'm running a 30 over 454 with 049 heads milled 30 thousandths and a summit 540/540 lift 228/238 duration cam.This thing will bang second real hard(th350, 3:23 rear gears) and it's shaking everything loose in the car.And I love it.A very simple build up will result in an easy 400 horse street engine.Cam,carb,headers,and intake.You know the drill.Big block for me boys!

[F-BIRD'88]

Ok here is the cheap and dirty cure. Mill the heads you have as much as your machinist dares. use the thin LS-6 head gasket. Install a Comp cams 280H Magnum cam or Crane Energizer 282-H08 PN#10307 but advance it in the motor a bit more to get some cylinder pressure and torque. Say another 3 to 4deg. (102/103 intake C/L).
Put some gear in your Monte (Monte's are heavy slugs, don't be shy on the rear gear ratio 4.10's or higher ratio) and get a 11" high stall converter.
Give er all the initial advance it will take and 38deg total advance. Lock the timing curve out if nessessary. Do not use a single plane manifold.
What is the combustion chamber volume on the peanut port heads?

[jam1719]

I believe the cc on the peanut ports are 113. I will use the edelbrock rpm airgap. The rearend gear is a 3.55 for now. great advise from everyone. I'm used to running small block chevys and Pontiacs. Big block checvys are a good learning experience. Anybody want to buy the peanut ports they are new and never been ran. Looks like I won't need them.