I wouldn't suggest trying it. Why not undo the bellhousing bolts on the '94, then remove the body lift, install the body lift on the '96 and install the engine. The body lift should make it quite a bit easier to get at the bolts.

They may have installed the power train as a unit at the factory, but it doesn't mean you have the same access, as other things installed are going to be in the way.

If you use the engine from the '94, you are not going to get the OBD-II diagnostics that are in the '96. You'll also need to swap the engine ECU and probably its harness.

John B.