After I had driven and towed with my turbo conversion twenty years ago I spent a bit of time in the valve body of the trans. I made changes to spring rates and preloads to move shift points. I turned a new control pressure spool to get the transmission to ramp up quicker for the added low end torque and installed a low speed locking torque converter that I think would be to a V6 Toyota of the era. The first torque converter flashed to about 2100 RPM, great improvement from the 2900+ of the original. I soon shred all the vanes internally in that TC and the company then properly welded the next one. That one flashes to about 1800 RPM. With 4000lbs+ on a trailer you roll about 30 feet before the turbo spools but from then on the transmission is locked and positive. The 2100 was better off the line, as long as you do not care about the tires. It is interesting that in some situations like 35MPH in top ratio the engine will bog down, not common with automatics. It drives a bit like a manual.
Had I done all this work a few years later I may have known of the lockup converter as Kevin did. But mine has served fine for decades with no problems.