Wheel back spacing using a B body 8 3/4

Ok so after measuring 5 times it's final I have a 8 3/4 for a B body! From leaf spring centerline to leaf spring centerline it's 44" and from flange to flange it's 55"

Question 1) If I use this 8 3/4 whats the correct back spacing of the wheel I would need to use in order for me not to rub the fender? Whats the largest size wheel and tire combo I can get under it with and without leaf spring relocator kit? The wheels are gonna be either 15's or 16's on a 73 DArt Swinger.


Question 2) since I already have to move my leaf spring perches should I go ahead and do a leaf spring relocator kit?

This car is gonna be a street rod....don't know if that help ya.