I've got a '68 727 with TF2 kit. Converter stalls at about 2500-2800. Shifts fine. Full-throttle kickdown works fine.

At slow speeds, under a load (such as turning up an incline) it stays in 3rd and essentially becomes a dog unless I mash the throttle or manually downshift.

Is it possible to add part-throttle kickdown without changing the VB?

This guy promises an amazing transformation with a mod that costs as much as a new VB: http://www.brauerengineering.com/trans/index.htm