I recently swapped out the two speed auto in my 65 “442” for a turbo 350. I was going to buy the shift works conversion for the floor shifter, but decided to see if I could make the original useable. I removed the detent plate and cut back about one quarter of an inch from where the low position would be for the old two speed position. I wouldn’t use it for racing , but it works great on the street, allowing for all three gears.

 

Good job!