[rsavage]

If they are both 71's, the only difference would be the firewall. The cutouts for heater/ac boxes are different for ac than those found on non ac. High and low humps were found on any year and were based mainly on engine/transmission combinations. 71 and 72 cabs had suspended gas pedals with a cable to the carb. Earlier cabs had gas pedals that snapped onto two studs on the floor and the linkage to the carb was rods. 71 an 72 had a vent in the driver's side rear door jamb. Earlier ones did not. 67 and I think 68 also had handles for the emergency brake while later cabs had pedals. 71 and earlier rear view mirrors were mounted to the windshield frame. 72's were glued to the windshield. I probably missed something.