I have a 1970 Olds 350 with #6 heads. I'm having it bored 0.030" over. I understand the stock bore size is 4.057" and I read that the gasket-bore size should be 0.050" larger than the engine bore. If I do the math, that means a bore size of 4.137"? I'm using Speed Pro/TRW Forged 6cc Dish Top Pistons #2321F30. I also read that Cometic MLS head gaskets were highly recommended with a thickness of 0.027"? I'm just having trouble figuring out which head gaskets to order. Will these work? http://www.summitracing.com/parts/cg...ake/oldsmobile

 

Felpro 8141 should work, are you going to zero deck the block?

 

The bottom line is that head gasket selection is a function of your intended use of the motor and your selection of all the parts. The FelPro gasket works great but has an 0.040" compressed height. The result is a slightly lower CR. The Cometics are a fantastic product but more expensive. Your call if you need the slight increase in CR or not.

 

Sorry thats 8171. We need t know how far is your piston is in the hole. Shoot for 40 thou piston to head clearance.