My brother has a Cummins out of a wrecked Dodge truck in his 85 Suburban. It fits in there no problem witn no body mods. It actually looks factory. The motor weighs 745 Lbs. His buddy has a 2003 3/4 ton Dodge 4x4 with some very minor mods that runs 12's all day long. Check out this link, (not his truck)
http://www.youtube.com/watch?v=cV0XJePUitI