The Borg-Warner OD is simple to wire up. You can use a double pole/double throw switch mounted under the dash in lieu of the kickdown switch. You can use a Bosch type relay.

See this OD wiring diagram

"It's just a phase. He'll grow out of it." Mama, 1964

1956 Chevy 1/2-ton 3100
1953 Chevy 6100 "The Yard dog"
1954 GMC Suburban Now with a new proud owner.