Ford F150 - wheel backspacing question?

Hello to all. new to the site, first post!!
I will be installing fabtechs 7" ultimate system in my 99 f150. fabtech recommends a 16x8 wheel with 4 3/4" backspacing....I have found that this backspacing is hard to find. will 4 1/2" bs work with 315/75R16??

I had 4 1/4 backspace and now 4.5 and both worked

I'm running 285/75-16's on Eagle 16 X 8 wheels with an -11 mm offset and 4 inch backspacing, and they fit fine. Pics in my gallery.

That back spacing would work better. The smaller the back spacing, the more the tires will stick out of the wheel well. REMBER that back spacing and offset are two diffrent things. But to answer your question, yes that would be fine.

sounds good. I want the tires to stick out a bit....not skateboard style, but to have a little girth...just want to avoid rubbing issues...thanks for the input...pics will be posted when work is done
thanks again

up in flames f-150 has truly inspired me. unfortunately I will have alot of the same components, so hopefully I won't look like a copycat, I'll try my best for originality.....but you know what they say, imitation is the best form of flattery!!!

FORDS UP!!!!