largest rear tire on stock wheelwell 69 dart

-- Agree with mopowers. -- Here's a 68 Dart, that I built, I believe the spring off-set was 3/4". The wheels were modified Mopar 8" steelies, with a 4" backspace and 275/60-15" BFG Radial T/As.

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I did the spring off set kit and a set of factory 15x8 rally wheels and got 275 60 15s