If I remember right, the distance between the firewall and the radiator mount is pretty short. You have to cut the grill to mount the rad in front of the rad support. Time to drag out the tape measure.

I put a D 50 cab & front clip on a 77 Jeep J 10 that had an AMC 360 4v. Think I added 4" in the center of both fenders to clear everything. That D 50 cab is very light. That Jeep was a lot of fun. In 4x4, from a standing start, wide open throttle would jump the whole truck off the ground, but you had to wear a helmet or you hit your head on the roof doing 4x4 ditches and such. The jeep was junk, the D 50 was junk, nothing to loose = lots of fun. Gene