On a GM A-Body with a 12-Bolt Chevy and a set of lower SouthSide Machine Bars. With a set of airbags, how should they be aired?

 

Do you mean how do you inflate them ? Use add on hoses to inflate or change air pressure.
Or do you mean to what pressure are they inflated ? Start with 5 PSI in each bag. Add a couple pounds air pressure to the side producing the blackest tire marks.

 

I meant how much should each side per aired up? Since with SSM bars the vehicle does NOT squat anymore, but lifts, should the air bags be aired differently?

 

This was my procedure for air bags. I also had SSM bars on my 70 Cutlass. 5psi on the drivers side. The passenger side depends on your burnout. Start with 5psi in the passenger side. I used to do a burnout in the bleach box and see which way the car wants to slide. (99% of the time it will slide right) If it drifted to the right (passenger side) while doing the burnout you need more air in the passenger bag. We're talking a pound or two at a time until it no longer wants to slide left or right in the box. Once it comes out straight you're done. I think mine ended up around 8-12psi in the right bag. Don't go over 15psi