My PreRunner -> 4x4 Swap +Questions

Hello! I've got myself a wrecked 4x4, and am pulling parts from it to upgrade my PreRunner to a 4x4. I'm not set up for a cab/bed swap, so swapping the drivetrain is going to be more realistic for me. Both are July 1998 Xtra Cabs, which is an amazing coincidence, and I hope that makes it a bit easier to do this project now that the summer heat has abated a bit in my garage.

I've got the rear axle swapped over already, and dropped out the transfer case and front/rear drive shafts, and am preparing to do the front spindles and transmission, but had one question to go first:

Do I need to swap the ECU and loom over? I noticed it's a different ECU part # than my PreRunner, but I'm guessing there's circuitry for the front hubs? If so, how much actually needs to be swapped over electrically? Some threads I found suggested a full engine/transmission/dash loom swap, others seemed to indicate that the PreRunner ECU was enough.