Question on backspacing

[darcane]

I'm looking at some 17"x8" wheels for my truck, and found a set I really like. There are actually two from the same company that are very similar, but one is built a little stronger (good on a truck...). Unfortunately, the more stout of the two comes in a 4.0" backspacing, not the 4.5" that seems to be the best fit for a 17"x8" wheel. Am I correct in guessing that only 4.0" BS will rub on the fenders up front? My truck's lowered 2" and I'll be putting 2" drop spindles on it when I convert to 5-lug.

Also, in case I change my mind about doing the same size wheel all the way around, what backspacing is needed in the rear for a 17"x9.5" wheel?

I can't measure my own truck at the moment, since they get kinda pissy in my neighborhood about working on vehicles in the street, and my garage is full of broken bike parts.

[gr8scott51]

see "my rims.....hopefully"