I just recently bought some P30 (JDM B16A) Pistons. I have a GSR motor and the car is going in the shop within two weeks. My plan is to put the pistons in the GSR block which will create 11:6 compression with stock head gasket and no milling. I was wondering if I went with a 2 layer head gasket, I'd be at 11:9 cr. Would that be safe? Would running street gas be ok? I need help in deciding if I should stay stock head gasket and be at 11:6 cr or 2 layer head gasket and be at 11:9, and which would be more ideal/safe. I really want to go 11:9 cr, but don't know much about compression. Any help is much appreciated. Thanks.