1988 Suburban - Cummins, Body swap and Rear A/C HELP

[guntotn]

Hello, Hopefully I am posting in the correct location. I have a 1988 Suburban with a Cummins swap. I love the truck but the body has rust that is developing, thanks to Northern Idaho snow melt chemicals. I found a really clean 1989 Suburban in Oregon and I want to do a body swap. I would love to just slap the engine in that vehicle but the frame in my suburban was cut and altered to fit the 5.9 cummins. Here are a few questions and concerns I have. Sorry for the length of the post but I thought I should paint a clear picture to get a clear answer...

1. I didn't get an approval from DMV to do the engine swap in my suburban. Although the suburban was a 6.2 diesel so maybe DMV doesn't care?

2. I am not sure how a body swap works but both vehicles have titles so I imagine it shouldn't be that hard. My biggest concern is back to the first point. If I didn't get DMV approval for the engine swap will the vin inspector doc me or fine me for not getting an engine/vin inspection for the swap?

3. Do I have to register both vehicles before doing the body swap or can I purchase the other suburban, perform the swap then just show the paper work to DMV? My plan was to head to California and do all this work there as I have access to a lift.

4. If DMV is all taken care of then the vehicle I found does not have rear A/C. I like to install or retrofit the rear A/C out of another suburban BUT this does not look like an easy task as the lines look like they route through the frame. Has anyone else done this and what are my alternatives? With 4 young kids rolling down the window isn't always an option. (This is our main driver)

The new suburban is extremely clean so I really don't want to pass it up as is the exact colors I have been looking for so I will save a lot of money not having to buy new panels to try to color match my interior. My current suburban has 3 rows of gray leather seats from a 2015 Honda Minivan so it will match fairly well. I really blew it by using the donor vehicle to do the swap as it wasn't as clean as it should have been. Lesson learned!

Thanks in advance!