Your rubber mounts are much more "straight" forward than the early model solid metal ones. You may still want to shim some if there are serious issues.
I suggest you first jack up the car on the frame, and run a level across the frame to insure it is square front and back. Now, loosen the body bolts and wedge the body up to allow access to the old mounts. Remove and replace one at a time. You will have to get creative here whether you have several strong arms come over, or rig a hoist, jack to lift and tilt the body. Set the body down on the new mounts and recheck the level of the frame. Now, run a level on the bode from side to side. At the same time check your door gap and fit.
You can add/remove shims as needed to get it perfect. Heck, it may work perfect the first time around.
I think you won't have any shim issues anyway since you are running rubber/poly mounts in those year models.
Plan on a whole Saturday and maybe more as often the body bolts are rusted in place and have a habbit of snapping or twisting off in the body mount.
