Well I haven't even dialed in my stock cylinder 4 mil and I just bought a 421 drag ported cub kit from Kevin Herr. I was so impressed..and everyone else for that matter... that seen that lil bike run. Low 4.4's on stock frame, 6"swinger, inframe CPI's on gas!! It's a Lil beast fa sure. Well I couldn't resist anylonger! Probably have some excellent stock jugs 65m pistons, drag ported by Kevin up for sale shortly.