Mine had a crane on it and the frame was bent down through the doors. Did not know until I got the doors and rear armor on. Ended up bending the frame up some with an I beam and 20 ton jack. Still needed a 1/2" shim at the front of the bed and the firewall support to get the doors lined up.
Yours looks to be off the opposite way. I would check to see if the frame is straight, the bottom of the frame along the engine, the top at the doorway and the rear behind the axle should all be parallel. You may need to do what I did, bend the frame....