In short, they do not interchange. My 86 carbie coil/ignitor are not the same as for my 87 EFI setup.

On the alternator, the regulator is integrated into it. You will want to grab the alternator mount as well, as the 'ears' are on the outside of the bracket, not the inside.

Yeah, it'll all bolt up.

I've thought about doing this with my 83; a little more work than if a 2nd generation truck, but not impossible. I've got to scan my 83 FSM schematic for someone; PM me if you move ahead with this for a copy. You can use the diagrams sticky'd here for the EFI part of it.