The Pirate Jack kit is the same one I mentioned earlier from MBM. It’s a 73+ disk brake swap with large ball joint spindles. The only difference between it and a 73+ conversion is that the rotor/hubs are drilled for 5x4 and the center register is turned down slightly (but not enough to run all of the factory SBP wheels).
Last I heard, DoctorDiff could provide those rotors as well.