I don't want to hijack this thread...but I'm hoping Bill Hanlon can provide more details on the year of rotor and caliper that he used for his conversion.
I'm looking to do something very similar on a 39 chevy 3/4 ton truck. I was just researching GM 4WD rotors.
I assume you reused your original hubs and bearings and made a bracket for the caliper.
I want to keep my truck all GM. I don't want Ford Mustang parts on my truck!

Thank you
Brian