It's my understanding that most of the Napco trucks used a dana/spicer transfer case, model 23 & model 24. However, some did use the T32.
This post has some good info. I'm still trying to read through it all.
https://67-72chevytrucks.com/vboard/...d.php?t=320260
On page 13 of that thread, you'll find this:
Here's a T32 that might be out of a Ford truck converted by Napco, although I don't see a Napco tag.
https://www.ford-trucks.com/forums/1475895-napco.html
Here's one in a 55 Chevy 3/4 or 1 ton truck. Driver side drop. I'm wondering if the same case can be used for driver or passenger side drop?
https://barnfinds.com/bf-auction-195...o-ending-soon/
Somewhere above someone mentioned taking a transfer case or big part through the airport. I did that several years ago. Had a reason to travel to Philly on business. Shortly before the trip I stumbled upon a T32 on ebay that was just listed as used transfer case. Turns out the guy was cleaning out his fathers garage. His father owned a plow company. The son who I met was driving an F600 Napco converted truck when something popped in the case and it wouldn't move. They swapped in another used case and left this one in the garage for the next 40 years.
I flew in, had my meetings, went to meet this guy at dinner time, paid him and put it in the truck of the rental car. Went to walmart and bought a cheap set of Stanley wrenches, some rubber gloves, an aluminum baking tin, some paper towels, and some boxes/packing tape. In the walmart parking lot, I took the case out and started working tearing it apart. I bought an aluminum baking pan to drain the oil in, then poured it into a two liter bottle I found in the trash. I left that by the door of the pep boys service center next door so they could recycle. I tore the case apart and ended up putting it in 3 boxes. Even the case by itself it pretty heavy.
The next morning, I drove to the rental car drop off. You should have seen me shuffling those heavy boxes! Then I went to the Philly airport. I assumed I was going to have to pay $100 or more to ship it. Well, it was my lucky day. Their systems were down and they were manually ticketing everyone, so they couldn't charge me! At the Atlanta airport, I rented one of those luggage carts to get me to the shuttle bus to my offsite parking. IT was quite the adventure, but well worth it. I put it back together and have it under my workbench in case I ever need it. I'll try to pull it out and get pics when I can, which will probably be in a couple of weeks.