Hey all -- I'm installing a cc503, 1.6RR, headers, 918 springs etc and i'd like to replace the head gaskets while im in there.

I was thinking the Fel Pro .039 gaskets till i came across these:

http://store.summitracing.com/partde...T&autoview=sku

Does anyone know if these gaskets would up my compression alot and add power? Would it hurt my bottom end more then its worth, and would they last?

I've never seen a review on these gaskets really so i was just curious.

Also, does anyone know how much compression id gain from the .039 to .021?

EDIT: So i looked it up in a calculator, 10.73 with .039 and 11.25 with .021. Would that help performance alot, and would it really hurt my bottom end? It has 130k~ so Id like to keep it for alittle longer atleast.

EDITx2: so I noticed that the .021 would be too small because the clearance on the valve and the piston?