Theres a guy on craigslist that has a PW50 in pieces, but it has a new top end. I am thinking of picking it up for the engine, because my tri zinger engine is in need of a LOT of work and i heard that they are the same engine besides the top end. If I can just bolt in the PW50 engine and run that until i get my other engine finished that would be great! Would the PW50 engine fit?