727 TF3 problems and pressure test

Seems kindof a long-way around the block, since Chrysler already engineered a KD system.
I have not installed a TF-3 for over two, maybe even three decades. Back then, the TV and it's spring, IIRC was replaced with parts supplied in the kit, the line-pressure jumped up, and finally, the lever was tied all the way back; and all that was in the instructions.
Back in the early 80s; I set up one of my own that way, for a streeter, and within a week or so, I swapped everything over to TF-2 status.
TF-2 does everything TF-3 does, but with much improved street-driveability. After that, all my auto-cars have been TF-2'd.

I realize that you are coming from the other side, so, probably not telling you anything that you don't already know.