robinson racing has a good setup for the tranny thye also have a dual disk slipper kit to get rid of the pegs ,tower hobbies has the gears from RRP and i am sure someone else will help out on some otehr hops aswell
all depends on how much you want ot spend on it ,the possibilities are just about endless as too what you can do with the maxx
honestly thats the only problem with them,you have ot upgrade alot of parts to make them a good basher