I'm sure this has been answered a million times somewhere in the boards, but can someone please tell me the size of the chambers on the LB9.

I've got a 305 TPI that I'm thinking of putting some Pro1s on, 64cc chambers, but after doing some looking, I'm thinking it's gonna drop my C/R a little too much. Any facts and comments appreciated.

 

Hey, I believe they are 58cc. Did you do a compression calculations with new heads? It might not be as big of drop as you are thinking, maybe 0.5-.75? Pro Comps are aluminum so would be best to run high compression like 11.0. Check out chart on this page showing power differences from changing rations. Going from 10:1 to 9:1 ratio will cost you 2.9% in power. So that would be 6-7 HP for 200 HP engine.
http://www.popularhotrodding.com/tec...ech/index.html

Here is a good compression calc that figures out dynamic compression. Change in dynamic compression would be more important to know. Need data on heads and cam to get results.
http://www.empirenet.com/pkelley2/DynamicCR.html