Pilot shaft diameter

Yes you need a bushing and up here NAPA stores carry it.
It's kindof an adapter bushing, as, to do this right, your crank would need to be drilled and resized to fit the factory bushing.
After the bushing is in, you kindof need to "degree the crank" to make sure the centerlines of the crank, and of the trans, are on the same line.

Having said that, Since you have already resized the convertor register, just go get a BB to fit both the crank and the input, do not install any bushing, and measure the depth in the back of the crank. Usually, but not always, when this swap is done, the trans input shaft will be too long, and a portion of it will need to be sawn off. But, you gotta leave enough to be supported by the BB.
Alternatively, you can just go to the Dodge truck dealer, and get the BB from an early Dakota, for same application. I got me one of those in 1999, and it's still going strong.

As you are doing this swap, maybe keep track of all the parts you had to get to make it work. guys are always asking.

Btw
you know that there is a different clutch pedal for the slanty clutch than for a V8 clutch right?