largest rear tire on stock wheelwell 69 dart

No problem! Well, the SBP will help a little as that's a narrower track width than with BBP axles and brakes. But it will completely depend on the backspacing. Normally you should be able to get a 245/60/14 in there with the stock spring locations and no trimming with the proper backspacing, but, those Cragars probably don't have that.