Rembember the crankcase is cooled from the inside by the fuel going through it. Altough I agree with most of the posters, start with a stocker first then add the mods one at a time. That way you know what works or not. Just to give you a bench mark, a much modied Homie 25, 16x8 APC, 9100rpm, on a muffler not tuned exhaust.