I remember that article and modified my 727, must have been about 25 years ago. There was a big improvement to the 1-2 shift but it didn't do anything for the 2-3 shift if I remember correctly.

1970 Road Runner 505 cid MCH CNC ported Stealth heads MP 528 camshaft 4 speed GV overdrive 11.98 @ 117 on street treads