[dsraven]

the centerline of the engine needs to be at 90 degrees to the rear axle. you could install everything else however you want but keep those angles to be sure you don't end up with a vibration. the offset diff pumkin is just another angle for the ujoint to factor in but if you decide to go with a 2 piece driveshaft you could be in for trouble. ask any 4x4 guy with a lifted truck that has a 2 piece driveshaft and he will say (or lie) that there is never any vibration. the front ujoint being a down angle and the rear u joint being an equal up angle cancels itself. the front u joint being also angled to the side to line up with the pumkin will also cancel itself if the rear angle is the opposite. thats why you gotta keep the centerline of the engine at 90 degrees to the diff. use a plumb bob and mark the floor under the cente of each part and go from there.