Widest wheel with Mopar offset spring kit on 68 Barracuda

sorry, that 50 series on the barracuda was stock spring location and ss springs. It also was a notchback coupe.I also had a 73 340 duster with stock springs and ran a 12 inch rim but dont recall tire size other than they were minimum 12 inches wide if not more. you have to find the right inset and offset of rims ,the rims on the 73 were steel and had a 10 bolt pattern so you have to look and measure