1970 Short Step Wheel/Tire Size

[bzblaine]

I have a 1970 short Stepper. I'm wanting to keep it stock height. 6 bolt all the way around. I have drum rear and McGaughys C10DBKIT up front. I do NOT want to tub it. I have coil, not springs What it the widest rim tire combo I can fit in the rear. With what back spacing? I'm shooting for 15s or 16s. What is a good size for the front? With what back spacing? Does anyone know the center bore diameter? I just want to order wheels and not have to worry about sending them back or machining them. Thanks in advance.