727 Lock up converter choices?

Don, you have more research to do. A 1988 fsm shows a lock-up converter for 904 and 999 transmissions only. The 727 is a non-lockup only. There is only one stall speed listed. If your trans is working properly, I'd just have a new ring gear installed. And adjust the bands, and change the filter.

Raising the stall speed in a truck is an iffy thing to do, especially if the truck is loaded. Too much slippage creates heat and foaming.

Changing the distributor curve might help. Milling the head might help.

good luck