Wheel fitment is all relative. However Backspace is not relative, it is an absolute measurement. It is from the wheel mounting face to the wheel inside edge.

Quote:
alex (warzon) said that i will need a deep dished wheel with a 3 3/8 back space
Oh, I get it now. He probably meant that a wheel with that offset wouldn't foul. Presumably he's allowing a certain measurement for clearance between the edge of the wheel and and the leaf springs. I'm not sure how much you need, I would say at least 5mm from the tire edge to the leaf, but would expect that to occasionally rub when cornering. Any tires wider than the wheel width (that is, any un-streteched tires) will rub before the wheel does.
So even if the wheel doesn't foul, the tyre might.