That linkage isn't simply for kick-down. The correct linkage geometry and adjustment are critical to all of the Hydramatic's functions.

Welp, I sold the poncho coupe after realizing I may not live forever. Young guy I sold it to had a solid build plan the includes a rebuilt 350 Pontiac motor and 350 turbo. He'll swap the 3.07 gears into the rear axle and it should be a great freeway flyer.