Learn me 73 chevy van based RV

so yesterday I bought and attempted to drive home a 1973 G30 van cum RV. after realizing the magnitude of what I have gotten myself into I am asking for helps from the people with more research patience than I here on the GRM board.

I have 8 lug duallies in the back that are 16 inch wheels. My research (and the front tires) indicate that it should be 16.5. I have no clue what the bolt pattern is on them and can't find any bolt pattern spec going back that far. The front wheel looks like a regular non-dually 8 lug wheel.
I want to convert the front to a 16 or 17 inch wheels so I can pick out some more aggressive tires as this will be a tow/recovery vehicle. The RV section will at least mostly be disposed of.
The front brakes are SRW not DRW. It has a th350 in it apparently. it also has a now non-running 350 small block in it.

The crux of my ramble is: What bolt pattern do I have? and what is it shared with?

Nearly all 8 lug wheels are 8 x 6.5. Late model fords are the exception. The center registers are different if that sort of thing bothers you. If not any 8 lug chevy or dodge wheel or a pre 98 ford will work.

Yep. 8 x 6.5

You might be able to convert the front end to take DRW wheels. From what I remember from cutting rotors, the spindle is the same, the hub/rotor assembly just has an extender.