You need a 7 inch rim with a 4 1/4" (factory bs. on rally and police wheels) or a 4 1/2" backspacing wheel to fit a 255/60/15 tire. The 4 1/2" bs. wheel will give maximum clearance against rubbing with stock to lowered suspension early A bodies with weight in the trunk or 3 to 4 people. I have tried quite a few different tire and wheel combos on my 66 Dart over the last 25 years, and the 7" wide 15's with 4 1/2" bs. wheels and 255/60/15 tires fit the absolute best. Without inboarding the leaf springs for more clearance.
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