I think you are crazy putting much effort into something that old especially if it is not in very good condition otherwise. I have never done a van motor swap but think I would do it this way if it were me. Lift the body off the frame and then roll the motor out on the frame and wheels then have all the room your would ever want to do the swap. However the factory puts the motor in, is how I think your should take them out. On unibody cars that means the assembly comes out the bottom, on something with a full frame often the whole front "clip" will come off, on a van I'm sure they must assemple the frame and running rear and then add the body on top. Like this video