I have fmf fatties, vf3 reeds, a pro design cool head (unaware of dome size atm), about to have +4 timing, and also about to install a 2into1 carb kit. The guy I'm buying the carb from says I need to run 100 octane with +4 timing. Is this true? Also what dome size do you guys think I should run for best performance in trails? I'm trying to have everything together so when I get it I can install it and ride but I don't think that will be the case.