Measuring for Backspace Front Wheels

Since wheels are so expensive and nobody wanted to return them without a restocking charge and for me to pay shipping both ways I bought a Percy's wheel right. Worked like a dream.
I have 17's on the front of my car 225 45r17 rims are 17X8 with 5.5 inch's of back space, steering in full lock puts the tire quit close to my sway bar, but clears all suspension components. This is on a 65 Cuda with wilwood disc's.