best rear disc brake conversion kit ?
Doctor Diff kits are pretty good and they can utilize factory tapered bearings unlike most other kits. Give Cass a call. He's a great person to work with.
10.7" kit:
http://www.doctordiff.com/rear-disc-brake-kit-10.7-rotor.html
11.7" kit:
http://www.doctordiff.com/rear-disc-brake-kit-11.7-rotor.html
Print