I believe the rear is a 373 or 411. and it is my understanding the powerglide and T350 have the same final drive. its 1 to 1.. so no improvement switching to a T350.
4L65E with TCI stand alone controller. TPS inside the car on the firewall. Piggy back the cable from the gas pedal to the TPS (section of Harley clutch cable). Vary shift points and line pressure relative TPS position, adjust lock up from a timer. All makes the differance from a car that makes it down the street to a performance car that's fun to drive. Just my$.02. By the way, I see Mike Hohnstein has modestly chimed in. For those that don't know Mike and his background and history, he's a transmission God and a visionary.
I am assuming the PG in there now has the factory TV rod in place, if so couldn't you just run the cable to the TV rod place on the throttle arm and make a bracket for the outer cable? Seems simple, am I missing something here?
Like chopped 51 showed you in post 8 Its not really rocket science although some fear the 700r4s because they can slip and burn up if this cable isnt adjusted properly or travel the right arc thru the throttle stop to full. a line pressure test and a person willing to play with the geometry of the cable fulcrum point and mounting stay will succeed and be very pleased with the outcome. This type of line pressure system thru cable feed back isnt all that tuff to outsmart..baby steps