Roll the fender in "IF" it needs it & can be done. Some folks use a wood baseball bat between the tire & fender to do it.
BUT I'm wondering if you have spring problems or a REALLY wide tire/rim on it or the back spacing on the rim may be wrong.
I ran stock GM Rally 8" rims w/235/70/15" on my 63 & 65 Chevy and never rubbed anything.....joe