Im playin around with the same setup. You can mix in pump gas with race fuel to cut cost. The lower cc dome the hotter your engine will run depending on your riding style with race gas. Im going +4 with 19cc domes mixing race with pump. Didnt check compression yet but should be above 150. I used to just put in any old gas but now iam playing around with higher compressions. Iam no expert but this is what iam trying.