Just bought a "new" 1990 4 Runner with 45,000 miles.(Rich man had put it in storage) It has never been off roaded, but it came with aftermarket 17" rims and all-terrain tires. I want to replace them with skinnier 15" tires so I can put the running boards back on without them rubbing. There are lots of used 4 Runner tires and rims for sale on Craigslist, but I am concerned about getting a set with the proper backspacing, etc.

I understanding I need to be looking for rims with 4 3/4 in. backspacing. What else?