For a second gen 4runner is 4 inches of backspace ok to have. I know 3.75 is just right cause im running 15x8 wheels with 3.75 BS, my buddy has a 94 runner just like mine and there are some wheels he wants in 15x8's but they are only in 4 in BS.
Are there any problems from this much BS? Let me know fellas, thanks.

 

4" BS is normal. It really depends on what size tries he gonna be running...

 

Actually, stock is 4.75":



So anything less than that works, the less backspacing the wider the wheels and tires will stick out and the more likelyhood of rubbing with oversize tires:

http://www.4crawler.com/Diesel/Tires.shtml#WHEELS

 

yea, i meant 4" BS is normal as in common.

 

cool thanks guys, he gonna just be running 31x11.50's so he should be ok.

 

That'll be perfect.