sidewall bulge measurement ?

Thanks guys for your help ! I have a 70' Dart Swinger that's mini tub'd , springs relocated and as many of you know , useing 15"x10" rims and the 325/50r15 tire in this situation there is very little room for error . I just need an accurate , real world measurement . Thanks again guys , much appreciated !!!

You might as well figure just over 13", especially since you are using the recommended average wheel. Based on my experience, allow about 1/2" clearance on inner and outer fenders. Otherwise they will rub. Good luck.