These guys specialize in early Dakota swaps, including 440's. Might wanna give them a call.
ALso some helpful mounts and plates here:
Emissions checks? That's a whole other ballgame. If the OBDII functions are not an issue, you can rework things to a more analog nature, gauges included. Transmission choices? 3-speed 727 Torqueflite for big block, or 727 for smallblock with an adapter plate, or even the A518/46RH with that same adapter plate. The stronger setup would probably be the big block 727 with a Gear Vendors overdrive unit. Either way, a solid towing setup will run some serious green. Will need a shifter cable. You'd come out MUCH easier looking for a well-maintained 1993 or earlier truck and doing the conversion on that, but that's your call. Just know your truck is likely to be sidelined for a while. Unplanned problems, custom pieces, all that. For all you're planning to do, you're in about what it'd cost to just supercharge your smallblock.