Probably the best way to solve the problem is to procure an aftermarket column designed for an automatic transmission. It may require some modification to the steering shaft and rag joint but would make a big difference. You are probably limited with wrecking yards where you are to find something else that would work. An 88 truck engine and transmission would mirror what you have except for the throttle body injection, computer, and wire loom. Sort out the shifting issue and you should have a good driver.
Fred


1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine