1965 Valiant disc brake upgrade

You're going to have change your wheel size. 13" won't fit any of the disc brake setups. I would go with the single piston (73+ a body) setup because the parts a super easy to find and you have a much much larger wheel/rim selection. Plus with just a caliper adaptor you can run/use the 11.75 rotors (these require 15" wheels though). Just know the the bigger the wheel/rim the best tire selection you have.

You need at least 14" wheels minimum to fit you K/H brake setup. Oh and use STAINLESS STEEL pistons in the calipers. Don't forget the disc brake master cylinder.