if they interchange with a normal 2wd truck you can just use the rotors from a newer truck in the 70's along with the spindles and you will have disc brakes
That would be real nice......if it would bolt on, but it doesn't. The '72-up Pickups are ball joint type front ends....the A-series Vans/PU's are kingpin. Someone does make a kit for them however, I just can't remember right off hand who it was.