Picking heads for a 383. I always went with smaller combustion chambers,64 cc, to keep the compression up. Now I'm wondering if I shouldn't go with bigger,72 cc. Want to use pump gas. Also thinking I can use a higher lift cam with the larger chamber. Might throw a small blower on this later, Weiand 177, so I need to keep cr down. I never hear much discussion about the different size combustion chambers. Any ideas, theories, or suggestions?

Anybody?

It depends on what you have now for pistons deck hgt, cam etc. & what compression you want. Post a little more info ;)

I'm in the planning stages, so I don't know the deck height yet. Flat top pistons with about 6-7cc dish. Cam with about 236 @.050 duration and .500-.510 lift. Thinking I don't want more than 9:1 cr if I throw the blower on later. I'm just trying to figure out how to pick a head with different size conbustion chambers. Do you pick it after the short block is built? Do you pick it according to what you need for a cr? Does the larger chamber help flow at all? Does the larger chamber give you more room for valve to piston clearance? Thanks, KJ

KJ,
you are going to need dished pistons to get to 9.0 in a 383. A flat top 383 with a 72cc head is going to be about 9.8. A 64cc head about 10.7.
This is assuming .010 deck & a ..039 gasket
The heads are capable of flowing equally well assuming an efficient chamber shape.
You can have a little more valve clearance in the bigger chambers depending on design but not necessarily. Depends again on the head design.

Hey Mike...I just realized your not that far from me..Im in Redding. I will have to stop by your shop sometime.
Jim

Originally posted by bigjimzlll:
Hey Mike...I just realized your not that far from me..Im in Redding. I will have to stop by your shop sometime.
Jim -
Hi jim,
Any time, our shop is located on our property 2 miles out of Laytonville, about 40 minutes above where hwy 20 runs into hwy 101 :D