Air Ride Questions

Hello Guys,
Im Having An Air-ride Cool Ride System Installed On My 71 Nova. Im Gonna Use An 18" Wheel But Im Not Sure How Much Backspacing To Use On An 7"Wide Rim. I Odviously Dont Want Tire Rub On Frame Or Tire Rub On Wheel Well Lip When Car Is Slammed. Im Only Having The Front End Bagged. If Anyone Is Using A Similar Set-up, I Would Love To Here From You.
Thank You, Project Nova

I don't know about all systems, but the one on mine when its slammed, you don't move the car. I have what appears to be stock size tires and when you dump the air bags it sits right down on the tires. You can't turn the wheels. It must have cost a pretty penny to put that system in, in my opinion wasted money. Still thinking about taking it out.

Don

If I Was Foolish Enough To Try An Justify Every Time I Spent Money On This Or Any Car, I Would Have Stopped Building Cars Years Ago.the Installed System Cost Me 1200.00. Small Price To Pay For An Awesome " In The Weeds " Look... At Least For Me