46re

TT5.9mag said
Just found this. Still looking for the electrical side of things.
A518 A618 46RE 47RH 47RE Valve Body Reprogramming Kit (1990-2002) Full Manual Control-Race TFOD-3

That is likely the very kit I was thinking of when I posted. I bought one have not (yet) used it. Unless I misread their website it truly will manually shift an RE