how thick of a hg

[Joey89mr2]

I'm in the process of building a 1620 with a silver top bottom and a large port head. Today I was cleaning all the old hg stuff off the 20v block and I decided to stop for the day. so I placed a small port head I had laying around on top (without a head gasket) so nothing would get in the cylinders, and that's when I noticed that the pistons hit the head. So I was wondering if the OEM 16v head gasket I got is thick enough. Would you guys recommend me getting a thicker one or what please and thank you

[dr.occa]

I would go with the a 1.6mm or .060" Cometic head gasket (81mm bore)

[Joey89mr2]

Would I run into a problem running the OEM hg? Would I need the block shaved with a cometic

[dr.occa]

Unless the head or block deck were warped, I would not shave either. The Cometic HG is a better gasket than even factory stock. Compressed, it is still thicker than a factory hg.

With a complete 20v bottom mated to a 16v head, you'll already get a slight compression boost.