Update: Haven't been in the garage as much as I should. I have decided in the interest of getting the project back together before I deploy again to hold off on the coil conversion and just swap over the leaf spring parts. I have the front shackle mounts off of the 3/4 ton and mocked up on the 1/2 ton frame.
Lining the mounts up on the front is very easy as both the 1/2 and 3/4 trucks have the body mount brackets in the same location and three of the holes in the shackle bracket are riveted through the body mount bracket. The rear should be fairly easy as well but will actually require some easy measurements.
I do plan on reinforcing the front frame section but haven't decided how yet. I will be relocating the sway bar crossmember which should help keep the frame rigid up front