The F9100 is the newest airspring development. With a 6.5" diameter and a 2000 lb. load capacity, it is perfect for El Camino installations that require some extra "oomph"! The upper cap and lower piston have been designed to fit directly into a GM rear coilspring mount. I have a new rearend and the lower cap is alittle beefer, it was off by a 16th to fit the lower spring mount cap I used my dremel hone it out. Later I spoke with Airride and they told me to remove small cylinder on the rearend and let the lower piston sit on the flat base with the bolt through it. They claim "NO adapter mounts needed, But you will need three disk type plates per side for mounting at $10 each. They have also located the air inlet on the side of the upper cap for easy airline routing...but no more trying to gain access to the cramped area between the frame and the body to install the airlines just the mounting bolt. I had to trim just alittle of the inner body to get my wrench in to tighten it up. For now I have them setup with a filler hose till I get the budet together for the front. I am very happy with the end results a great ride with Edelbrock IAS shocks and 2000 lb. load capacity. I guess when I finish the system I can set really lower like I saw at Daytona this weekend.

if you had to estimate the overal improvement in handling over stock, how would you describe it? Im probably putting airride on my 72 and Im curious.

Yes, I feel the airspring did improve the ride in my 71 Elky 100% better and ended overload sagging with a 2000 lb. capacity.

You need to look at the whole system to get a great ride. Decide what your driving style and needes and wallet can handle. I have a 1 inch rear swaybar to help in the turns. IAS Edelbrock shocks for the bumps stuff and stiffer swing arms help with traction. It feels like I'm on rails even on poor roads.

Unless your keeping a stocker, most of these are easy and greatly improve your ride to a true comfortable Sport suspenion vs stock slop ride.