motor swap

I have a 99' Scrambler 400 4x4 with a cooked motor, that everything else is good. I also have a 2001 Trailblazer 250 2x4, that needs alot of work, but the motor was rebuilt last year. The plan is to swap the 250 motor onto the scrambler frame, removing radiator and what not, since the 250 is...

I have a 2003 polaris 700 carb sportsman with a blown motor (it slung a rod out the side and spun the bearings in the crankcase). My question is I will have to get a new motor. The head is alright on it and was looking into buying a new motor I was wondering if anyone has done this before. Also...