friskyjake

A friend [way up north has no internet] has a 65 cutlass conv with 52,000 miles on it & is wondering is there a way of lowering the c/r of the 330ci engine, without putting in pistons in it? Is there thicker head gaskets? High octane gas is not available in his area [expect aviation fuel] Thank you

coppercutlass

Thicker gaskets are the easiest way i know of most replacement head gaskets are .040 o.e is usually .017-.022 you can also buy thicker ones from corteco they are expensive but reuseable from what i have been told.

DeltaPace77

I'd be a bit careful of the amount you raise the heads from the block, as can cause intake manifold fitment/alignment issues. Mixing in a few gallons of 100+ octane racing fuel would be easiest if availible. Not sure of AV gas, as think the octane's rated differently. I used bolt on alcohol/water injection years ago, but not sure the availibility/cost of these now.

Rickman48

Shouldn't have any 'fitment problems' unless you go over .100, and then there's ways around that.

coppercutlass

I agree with deltapace77 dont use too thick of a gasket measure deck height , piston dish, etc. to get your total real compression. If you decide to go to a thicker gasket and the intake does not match you can get it milled i paid 100 to get mine milled after i milled my heads .024 that was with an edelbrock intake though.

Rickman48

But you're adding space, not dropping the bolt holes lower!
Thicker intake gaskets and a heavier bead of silicone might be needed!

friskyjake

Thankyou fella,s for your advice I,ll pass on the info.