Frank, note that per the chart I was looking at, those are output shaft rpms, not engine rpms. There is no TV effect on lockup at all, near as I can tell. Totally speed dependent which seems dumb to me, too.

My observed lockup was at about 39mph, don't remember rpms, and I guess it's a function of tire size for the differences.

Fiddling with the TV adjustment will change kickdown/upshift, but not lockup. You'll have to change a valve spring to change that, looks like...