Phil, please clarify your wheel dimensions. You mention "back set" and "set back". Neither of those terms is a recognized wheel specification or measurement.
There is "Back Space," which is the distance from the wheel mounting surface to the inboard edge of the rim.
And there is "Offset", which is the distance between the centerline of the wheel and the mounting surface. This measurement is the most crucial of the two because it determines where the weight of the car is carried on the spindle relative to the wheel bearing.
