Well, did about half the research I should have but cracked the wallet open anyways. I have a crosworth 13.75:1 piston and gytr cams on their way for my 08 yz450f. Few questions some of you might be able to help me with. Any issues using an oem head gasket? Or oem valve springs? What will these parts do to my jetting? And what octane fuel can I get away with at sea level? Any help at all would be great as I'm not finding much with this compression ratio and cam specs.