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Author Topic:   BEST SBC HEADS
stealth
Member
posted January 28, 2004 07:32 PM
I HAVE TO RUN STOCK GM HEADS FOR MY CLASS OF CAR. WITH THE PISTONS I HAVE FOR MY MOTOR(406), AND THE 461 HEADS MY COMPRESSION IS 12.9/1. I WOULD LIKE TO FIND SOME LARGER CHAMBER HEADS SO CAN GET MY COMPRESSION DOWN TO BETWEEN 11-12. HOWEVER I DONT WANT TO SACRIFICE THE FLOW OF THE HEADS WITH SMALLER RUNNERS. DOES ANYBODY HAVE ANY IDEAS ON WHAT HEADS WOULD BE GOOD FOR THIS. CASTING NUMBERS WOULD BE GREAT. MOST SMOG HEADS OR LARGE CHAMBER HEADS WILL LOSE ABOUT 25-30 CC ON THE INTAKE AND EXHAUST RUNNERS. THANKS


chomme
Member
posted January 28, 2004 10:55 PM
441's are another good 76cc head. Tere are guys around here shavin them puttin in big valves and running them in there pro am.


racer17j
Member
posted January 31, 2004 08:50 AM
why are you wanting to go with less compression ?


mike10az
Member
posted January 31, 2004 04:37 PM
my guess is he has to run pump gas or low octane gas and the 12.9 compression is just a bit too high but who knows?

[This message has been edited by mike10az (edited January 31, 2004).]

dan63
Member
posted January 31, 2004 10:10 PM
i would agree dan pistons are alot cheaper way to drop your comp then a set of heads you's got a ggod set of heads now if i had the option i would definaly keep them on


Ego Racing
Member
posted February 01, 2004 07:54 AM
You didnt say what pistons you have but if they are Forged solid dome pop ups or a GOOD flat top you can have a good machinest cut them to the compression you want. Just contact the pistom MFG and see what the minimum top thickness you need.


Raz_900
Member
posted February 02, 2004 10:38 AM
I agree with the new piston option. The 461 head has good quench areas and you'd lose that with the 76cc heads. Reverse dome pistons can be made to drop the compression to way down (22cc reverse dome would be about 9.5-9.8:1 with 64cc heads) ).

A 7cc flat top is about 11.5:1.

smayo964
Member
posted February 10, 2004 11:04 AM
In response/question to what Bigdaddyboz said about the 441's, are they a good set of heads? I have (3) sets of them in my shop and I'm debating on using them. Two sets have big valves and one with the small. Can they be ported adequately or should they be left as is? I noticed a consistent "pocket" up under the intake valve seat opposite from the intake runner. Will that hurt performance? Need some assistance and appreciate the help. Oh, these heads will be used in a mod engine(s). Thanx.

[This message has been edited by smayo964 (edited February 10, 2004).]

nolimit92
Member
posted February 17, 2004 09:15 PM
Look for a set of 441X heads they only had them on 2 years of 400 engines 71-72. I had a set flowed and they flow better then stock double humps. The 441X casting is on the bottom of the heads. They are getting very rare but they are a 80 cc chamber and can be planed down to a 73cc very easily.

Mike

Ego Racing
Member
posted February 18, 2004 07:34 AM
Chevrolet used the "X" on the casting to indicate a larger runner volume. If you can I would run Vortec's. The engine will breath easier with them. I do not under stand wanting to keep a small runner and chocking the engine, you just do not want to go to large but with stock heads you are safe.
I small runner on a head is like drinking through a coffee straw.


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