[jimbob]

i would probably ditch those big old wheels

put some 2.2" back on ther, now it normally uses a 540 can so they should be alright and if gearing is limited maybe stick to that, depends waht you wanna use it for....
if its for bashing/speed maybe 19t 540 motor
if its for hard bashing/trials then wack in a 550 or 600 can and it should be all good