this is what you do get the tower tuned pipe set for st-15, duratrax ball bearing set for st-15, and the tower aluminum shock set for st-15, also any coling head that fits the traxxas pro 15 will fit the tower 15 so also get a powerline cylinder head for the pro 15, and as for the rc10 arms all the info you need is to do that is on the official st-15 thread so when you do all this including the rc10 arms upgrade youll have a truck that would probably have about 1+ horspower with the powerline cylinder head and tuned pipe and a nice wide truck that handeles well with the rc10 arms also a nice riged smooth truck with ball bearings and alloy shocks all together it will be simaler to the rc10gt in handeling and power oh yeah youve got to get rid of those crapy tires get some proline edge for the front and your choice for rear with all that you should be able to compete with it and even if all that cost as much as getting a rtr with those features its still worth getting because of the optional 2-speed tranny and you might want to get rid of that half ***** body eventually so you could probably get like a 99 gmc siera body for rc 10gt ps they can be made to fit the st-15 if they dont already or a f-150 or chevy whether you like gm or ford with all that its a great truck.