Yes, mostly... engine components (if both are 800) should be totally interchangeable. Skid mount locations may be different but Pro skid should mount into the Assault. Belt drive is another matter, I would just stick with the Assault chaincase / driveshaft, but you can switch them AFAIK you just heat up and remove the chaincase from tunnel, same for QD backing plate, put the QD backing plate onto the Assault tunnel (with appropriate adhesive), switch jackshafts and driveshafts and probably brakes and a few other things I am not thinking of... as long as the tracks are the same pitch (2.86 for example, for the 2.6" tracks) I would run the chaincase (which is also easy to gear down - bonus) or if you are dead set on a belt drive, buy a TKI kit for the chaincase and save a bunch of labor and be able to gear it down.
