ive been looking at piston kits for my car, looking at a wiseco kit. but on the size it says 81 or 81.5. think my motor is 81 stock so would it be bettr to go any bigger? If i get bigger what else would i have to do to make it fit. also some of the compression numbers are 8-7-1, 9-8-1, and 12-0-1. what do these mean and if im going turbo which do i want?