I'm not sure if the bolt pattern on Dodge and DeSoto are the same but I'm sure some Dodge pickups had floor shifts. I made an adapter to put a Studebaker Borg Warner T86 overdrive behind my Chevy 4cylinder. I put a floor shift top from a Jeep T90 on it. Three speed floor shift with OD. Where there's a will there's a way.

"I wonder if God created man because he was disappointed in the monkey?" Mark Twain