After months of fiddling around with various delays, I've finally been able to get back to working on the Charger. Ive been dissatisfied with the part throttle performance ever since I first installed that 10" high stall converter several years ago. On the advice of a few Moparts members, I called Lenny at Ultimate Converter Concepts. He was very helpful with advice and suggestions on what would work for me. He didn't try any hard sell type tactics. I went with an 11" unit with an estimated stall of 2800 rpms.
I removed and sold my Gear Vendors overdrive unit and went back to direct drive. Today I finished up and took the car for a drive. Some of the gear whine I was hearing at 60-70 mph is gone. I wonder if there was something associated with the slip & spline drive shaft that was responsible. Regardless, the car feels different. It now responds to throttle input like it should. I can tip the throttle at 40 mph and feel the car pick up immediately. Before, the tach would rise faster than the car would move. The car actually chirps 2nd gear at part throttle, the first time in several years. I'm still running the old 3.91 SG 3rd member but I have another one with fresh 3.55 gears waiting to go in once I swap to the 528 cam.
It is great when things work out.