Iv read and heard that some people only use the middle layer of a OEM head gasket to acheive a higher compression ratio. Is this safe? Will it seal properly?

Also, are GSR and LS head studs the same size and legnth?

 

8 out of the 10 headstuds from an LS can be used for a GSR block B16 head, but 2 of them are too long. As to a GSR head/GSR block, I'm not sure.

 

Anyone on just the middle layer of a OEM head gasket?

 

You'd better hope that the deck and the head are perfectly even if you want to use a one layer headgasket.