Should be pick up a VN 5L from 2k down. They're cheap these days.
IMO, if you're considering a v6 conversion, just go the EFI v8 instead. Same wiring/fuel system changes but it will bolt straight in depending on what box you run.

I just pulled the V6 out of my van to change to a VN 5L and T700. It went alright with the v6 but wouldn't have been my choice.