So I installed a TKO600 in my Dart, with the .64 OD. I love it, 80 mph at 2300 RPM. No trick synchros or anything, it shifts fantastic, right to 6000 RPM. I say throw the mechanical clutch in the trees and install a hydraulic unit. No more squeaky, rattling clutch linkage, and lots more real estate for headers. The worst part was cutting the floorpan open, it's an original 4 spd car....but that passed quickly when I drove it for the first time with the Tremec.
Just my opinion.