Earlier this spring I built a custom 73 Schwinn Varsity using parts from a 74 Le Tour & my parts bins. The crankset was the stock Le Tour unit paired with a Shimano HG 7spd 13-30 freewheel, I installed a clean used Suntour V GT Luxe RD, a NOS Spirit SL High normal FD and a 7spd chain with modern shifting cables using the stock Suntour Le Tour stem shifters. The results just blew me away, it shifts better & smoother then the best index system I own ( Tri color, XT) . I really didn't expect this kind of performance from a cobbled together drivetrain system of low end parts and the shifting of the SL FD is so good it just boggles my mind.
Glenn