Backspacing

I am almost done completing an XJ I have be building for the last year. It is all complete with the skyjacker 8 inch spring and 3 inch apacers and big off road 9 inch pack and extended shackles. Im putting 38's on it and I am buying new steel rims. What sort of backspacing should I be running. They are 14.50 and I have done major trimming. We tested a set oy 38 x12.50 SSR's and there was plenty of room to spare with no rubbing. I built mine a replica of his but neverr looked into the wheels. All I am asking is what kind of backspacing do I need and I am not too worried on how far they stick out. If there is rubbing there is more cutting.

THANKS

I dont give a $#!% about what it looks like but I don't want any control arm rubbing

how wide are you axles? that might help.....

i have a 3/4 ton in the rear and a stock front on an 88 in the front till I can find a d44. Any ideas?