First you need to define "drivability".
A 75 year old 3/4 ton truck is not going to perform or handle anything at all like a modern vehicle no matter how well restored. Merely adding radial tires makes a dramatic improvement in handling and ride quality of any antique vehicle but all of the technology on the truck is still 75 year old design.
I don't own any modern vehicles and use all of them as daily transportation and work vehicles, including the 1950 1/2 ton pickup. In fact, Ol' Roy is my primary work vehicle. I don't ever expect any of my vehicles to perform as a new vehicles and don't attempt to drive them as such.
If your truck is already completely restored, you'd be better off selling it and using the money to buy a customized pickup truck that handles the way you think you want yours to handle. No amount of "upgrades" to your existing truck are going to make it perform or handle anything like a modern vehicle. You'll spend thousands of dollars more on the truck and you'll still be disappointed.
There are plenty of AD trucks out there for sale with V8 engines, Mustang II front ends, and automatic transmissions. Shop around for one of those and go test drive it. See if that's what you really want.
