Backspacing

Have recently purchased some 31x10.5x15 tires to put on my 1990 comanche with a 3" lift. Should I use the stock 15x7 rims or buy something with less backspacing? I do not want to do any trimming so any first hand experience would be appreciated.

I ran 31's on stock 15x7 wheels with few issues other than some rubbing on the LCA's. With 3" of lift, you should be fine.

I wouldn't expect any problems in the rear.

Less back spacing will make the wheels stick out farther from the body, thus increasing the chances of rubbing. At 3" there won't be much interference anyhow, probably only when flexing while turning, so it is mostly a matter of personal taste and $. It doesn't cost much to have tires remounted on wheels so try it out on the stockers, and if you don't like it, then go on from there.

Just to clarify what footdale is saying, less backspacing causes the tires to sit out wider increasing the chance of rubbing on the fender, but REDUCING the chances of rubbing on suspension parts like the control arms, shocks, etc.