SB rim sizes

[808_67C10]

So, this isn't my first rodeo but, the problem I have is, I don't have the truck to measure and see how much meat I can fit into the wheel wells.

I have also looked at about 20 different threads on the topic without definitive answers.

I am in Hawaii and picked up a truck in Cali (no rust, and cheaper than I can find here). The truck is on the way here but, want to order some wheels. I would like to run 20x8.5 up front and 22x11 in the rear but... I am worried about backspacing and tuck-ability. - and how it will look.

Its an 85 c10, and it already has spindle/spring drop up front and just a flip kit in the rear. its running on rallys right now.... see pic

20x8.5 up front shouldn't be an issue based on threads, with 4.5" BS

Whats the most rim/tire I can run in the rear? without raising the inner fender or narrowing the rear?

I may bag it later but, I will deal with all the saws-all drama when that time comes.