Need help with wheel fitment.

[team39763]

I'm getting some 18's from a friend pretty soon.  He's not sure what they came from, so I'm gonna use adapters when I get them. But I can't figure out what thickness to get the adapters.  I have some specs on the wheels.  Can you guys tell me if they will tuck with the right tire?
  18X9 with 24mm offset and 5.91 backspacing and 18X10 with 22mm offset and 6.36 backspacing.  He said he got them from Mexico and he'll cut me a good deal on them if I like them.  I found a place that I trust to make me the adapters and they can make them as thick as I need.  Any help would be greatly appreciated.

By the way, my truck is a 1982 1/2ton(SWB) that will soon have a 4/5 drop. 

From my calculating, they should fit ok, but I've been wrong about a bunch of things since I started working on this truck, so I'd like some other opinions. Thanks.

[okuma]

I would order the spacers from 1" to 1 1/2" thick, because the wheels are so wide. I would also test fit the wheels before dropping it. once the wheels are installed you will be able to decide how much of a drop can you go with. all this because the wheels will scrape on the bed edges and the inner fenders.