My head's casting number is 3947041, here is the info i got on the head 3947041....69-70...302/350......"Right angle" casting identifier, 64cc chamber, accessory holes, good HP head

my question is what is the size of the intake runners?...would it be the same as the 3947041X head (165cc intake runner)?...also i have google the casting number several times and i keep getting 64cc and 76cc combustion chamber sizes and im not sure which is right.

 

anyone?

 

what did they come off of

most of the guys who are know this kind of stuff are not always looking to talk about that old of stuff on these boards

maybe a corvette site

I dont know

 

They're pretty much identical to the 186 castings. Couple different intake valve sizes, either 1.94 or 2.02. 64cc chambers and 160cc intake ports. The "x" versions are same except +5cc's on the ports, if memory serves me correct.

 

the runner vol btween the two heads is more than likely the same ,163cc as the factory heads almost all have pretty small runners!

as far as the combustion chamber vol. could be either only way to know would be to measure yourself. hope this helped

that is a great casting though with some clean up! i have a pair myself

 

I plan on porting and polishing them hopefully get some more flow out of them...im building a 383 so do u think these heads will flow enough after the port and polish?

 

man these guys know their shizzel

I dont know if I will ever get that technical with stuff

the guys on thirdgen.org

ROCK