200 4R Install Questions.

Had not been on the site in a while. See that lots are going with the 200 4R. Talked to Art Carr years ago about these. Had issues with one in my Monti SS Aero Coupe. Ended up just the TV cable bracket letting the cable "pop out" when really hot (in AZ.) Cheap fix, Expensive problem, as a rebuild needed every time. so i have one in the garage as a spare. I read the info about building, need a Stage 2 most likely. '67 cuda 512 ci tall block, perf. RPM heads n M1 port matched, Roller cam. Should be mid 600's hp n torque say's Hughes. RPM not much over 6k, dana 60, mini tub, caltracs. willwoods. have a rebuilt '67 a-body 8/3/4" 741 3.55 posi n 727. was going this way. looking for street cruising weekend 1/4 mile car. beat up new GTO's n Mustangs. need the OD for that...
Questions are, best gears. have 4.10's now in a narrowed dana 60 510 housing. 4.56-4.88-5.30 ? I did the calculator. want real world experience.
What's the best adapters, and who makes them ?