I have done this conversion. I replaced the Traxxas ESC with a sidewinder ESC, I had to make another motor mount to bolt the velineon motor up and replaced all the gears in the diffs and center tranny with the metal Mini-t gears (Ebay for about $11 a set). The truck flies and is alot of fun, it will do 50-55mph on a 1650 3s lipo. It was alot of fun to build, but as others have said, make sure you shim the diffs, I also shimmed the tranny, have not had any heat problems or any other problems for that matter. Replaced the servos with Hitec HS65-MG's that I bought at my lhs buy one get one free, because they had a huge overstock. I am posting a couple pics so you can see it, these pics are before the new motor mount(made from an old street sign with a dremel and a drill).