Transmission debacle

I'd clean up the 727, replace the front, kickdown (external and internal), and rear seals, Flush the torque convertor, adjust the pressure up, adjust the bands, maybe install a 4.2 kickdown lever, replace the filter and fluid and run it. Get a balanced driveshaft and have at it.

The sprag problem occurs when doing water burnouts and and overrunning the sprag.
https://www.hotrod.com/articles/15-tips-improve-727-torqueflite-trans/

My 727's do not have the bolt in sprag. Not a drag racer warming the slicks in a water burnout.