Buddy is working on a 62 B body, converting over to disk brakes using late model Aspen disks. Does he need to replace the lower control arms with the later b body arms?

Stock 62 arms and ball joints work.

Bolts right in. Probably need to change calipers in order to get a decent hose routing but the hard parts bolt straight in. Do a little searching and you'll find a number of tech article that cover this swap.

I converted one of my 62's over to Wilwood Calipers/Discs, but my big problem was I wanted to keep the 14" 200-S wheels that came the car. They now have 10.75" .81? Vented Rotors. That is not real beeefy, car stops OK, but I wouldn't go near a track, nor any mountains. I am planning on going to 1.25" thick x 10.75 rotors to give me a little more margin. Everything I got bolted right on.