rim width and back spacing

[duece05]

Need to get some 10" wide rims and wondering if 4" back space will be enough where I don't have 4" of tire hanging out into the wind. trying to keep this on a budget and 4" back space seems to be a standard. have searched thru the "wheel thread but didn't find out what I needed to know

 

[Hawgman]

basic rule is (and no, this is not 100% accurate, but damn close)

8" wheel = 5.5" back spacing
9" wheel = 6.5" back spacing
10" wheel = 7.5" back spacing

 

[duece05]

are the 7.5 B.S. a rim that jeggs or summit would have or would I need to go elswhere