I have been doing some research on the largest tires you can put in front of a standard 71 Challenger but I am stilll confused. I have new 15/7 classic cragars with 4" backspace and need to know if a 235/60 15 will fit with no modifications, if not what mods do I need to make. I need to order the tires this thursday so if someone has done this and it works please let me know. thanks