I need some technical info on a B-body disc brake swap

Just remember that the 71-72 B body spindles use a different wheel bearing than all the 73+ rotors. The rotors for those are specific to 70-72 E-bodies and 71-72 B bodies. Originally they were a 2 piece rotor, and for awhile they were quite a bit more expensive to replace. There's now a 1 piece rotor made to fit these applications, it costs a little more than the 73+ rotors but they're readily available.

You can also use a bearing adaptor for those spindles from DoctorDiff to use the 73+ rotors.