The Stovebolt Site Forums The Parking Lot Big Bolts Disc brakes for 1.5, and 2 ton trucks

Here's the condensed info for a 1.5 ton heavy and 2 ton disc brake upgrade.
No need to even remove the axle beam from the truck!

If you have a 1.5 ton with the light axle (thread or press in grease caps) or a 41-46 1.5 or 2 ton also with the light axle then first swapping to an AD 2 ton axle beam would be necessary. (Or consider a 41-46 heavy 2 ton axle and double check all the critical measurements.)

In addition to the info below you'd also need to narrow a tierod, this can be done by using the one that comes with the P-30 axle and cutting it approximately 9-1/8" shorter on one end and rethreading it to fit the tierod end again. Consider choosing the right hand threaded end, taps are more common than left hand taps, but left hand taps are available if need be.

The draglink will also need a solution and it should be reasonably simple to assemble from off the shelf ends (different lengths, threads, and tapered ends are available) and a sleeve to connect them, just as the P-30 used. If you have a ball stud type end on the pitman arm you can remove it and have it reamed for a modern draglink end, or can swap pitman arms for one from a newer truck with the tapered hole already.

Note that if you want to use the original steering box you want a P-30 axle as the donor, not a 3500HD axle with the different steering setup.