5.9 magnum automatic crank

I’ve read the ready to go as far as being able to put the roller bearing in, as opposed to an old-school bushing which I’d rather not use. But if it’s not drilled already I would rather have it done at a shop with this precision work.
That was my next question. The difference between the bushing and the bearing. Is that an either or type thing can I choose or does it depend in the transmission shaft and or crank ID?