If any one runs CPC heads I would like some input. I bought a set off e-bay the guy I bought them off of told me I have to run at least 110 octane fuel with the high compression domes. I called CPC and they said I should maybe mix it 20 percent race fuel depending on my timing. But he couldn't tell me what key to run or if I needed to change at all. If you need more info about my sled to tell me what I need the sled discription is givven in the T-cat won't rev past 7000 RPM post. I would also like to know if trail riding with these heads is going to cause problems. Its not my trail sled but if my other sled breaks I would like to know if I can ride it. Thanks for any info