Im running a ported 392 cheetah on 34pj carbs. 145 (i think) mains and 55 pilots. It needs more carb as its still rich even with the small mains in it. Love my cheetah, its got a wide smooth powerband. I hope to do some more tuning on the powervalves, maybe mess with springs in it. Like i mentioned before the best thing you can do is drill the bleed jets out to .125 (1/8 inch) its about the biggest you can reasonably go without getting into the thread. This is also the "lag" people experience and i think part of the problem with alot of cheetahs not "putting out". the valves cant react fast enough as the engine comes onto the pipe.