I'm looking at getting a rotating assembly but the compression ratio with the 64cc heads I already have it is 10.9:1 Which is too high to drive everyday. So my question is can I lower the compression some how and stick with my heads or will I have to get new heads? Now if I have to get new heads I was leading towards world casting sportsmen 2's or torquers. If I went with new heads what CC (67,72,74)would I want to get to keep the ratio within 9.5-9.9 using the rotating assembly mentioned above? I could really use some help in figuring this out thanks.

 

You could run a thicker head gasket,I can't tell you exactly how much which gasket will lower your compresion,you'll have to do the math.

 

Seriously you will have to give all the specs on your engine for this to be figured out. I don't even have a clue what you have as far as bottom end or heads.. so?
Plus there are ways to run much higher compression on the street than you might think, so how high do you really want/need?



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White 1986 Irocz, 305/383 with Edlebrock Performer-RPM intake and Performer #1407 carburetor, +110hp shot of crack, 700R-4 tranny, 3.25:1 rear, Mcreary Road-Stars, single 3" Borla exhaust, Linginfelter-TPI camshaft pulls 17" vacuum solid. N/A runs 10.9 @124, Crack-runs 10.3 @135... haven't run at track since Oct-99