largest rear tire on stock wheelwell 69 dart

hello, I have a set of 14x7 cragars and want to do the same thing basically. small tires on front and max out tires on the back. I believe the rims are the standard backspace. sure could use some help here. thank you brian

BBP or SBP, and what rear axle? Stock spring locations?

The "standard" offset on the 14x7" Cragars is probably going to be your limiting factor. A lot of those cragars have a negative offset, most are zero offset at best. And either of those situations will keep you from running the widest tire possible even with SBP rims and the stock spring locations. To be certain we'd need to know the backspace on those Cragars.