Can someone please explain the difference between standard size jdm p30 pistons and .25 oversize jdm p30 pistons? advantages? disadvantages? I am doing a b17 build with p30 pistons, I didn't really want to bore the block, just to keep it original, considering the fact that it is a rare motor. I ordered OEM STD size p30's and OEM rings. As long as my cylinders are round I should be good right? Thanks