I'm not certain about the 2.5 Rustler (as far as the engine mount/ clutch setup). I know that from the Pro .15 Rustler that the engine mount had to be modified a little with a dremel for recoil starter clearence. The stock clutch fit on the O.S. with no problems. The rear-exhaust stinger will only fit blocks with the standard, rectangular, side exhaust hole. You won't find a 360 setup for the 2.5, side exhaust is the popular thing now.