I just thought a bit more about what you said. That would not work because the extra 4in. was put on the front of the bed. To use a 79 bed on a 75 without cutting the bed you would need to cut and move the bed mounts back about 4in. and then also move rear axle back to fit. Or am I wrong?instead if cutting the box,i just move the rear axle back on my hzj75.