I needed something for carrying heavier loads and towing so I decided to try the Supersprings. I know there are different options (airbags, roadmaster, etc.) but I decided to go this route first. Anyway.... here's how it went.
Tools you will need:
(2) 3/4" wrenches
(2) 1/2" wrenches
Raise rear of vehicle and remove tires.
Loosen but don't remove the 4 U-bolt nuts that hold down the bump stop. Remove rubber bump stop. Re-tighten 4 U-bolt nuts.
Place mounting block between the factory U-bolts with the open ends perpendicular to the vehicle direction. Place the hole in the bottom of the mounting block over the bolt in the factory spring pack. Tap mounting block into position.
Decide which side you want to do first, keeping in mind that each spring can work on either side but there is a front and a back. The spring eye and roller bolts should be thread outward. Slide the spring in from the rear and position it above the mounting block with the short 90 degree shackle to the rear.
Ensure all brake cables are routed clear out of the way of the Supersprings blades; slight repositioning or the addition of a zip tie should help. Select either the upper or lower bolt hole position based on how much spring pre-load you desire. Upper hole will increase pre-load and vehicle ride height. Ensure that polypropylene (black) and steel rollers are reassembled in the shackle. Attach bolt on front with threads facing OUT.
Use C-clamp to pull down rear shackle. Use the Upper (top) bolt hole position. This provides additional vertical clearance to the frame. Install polypropylene and steel roller assemblies and snug tighten nuts. Eye bolts of all shackles are pre-set, do not tighten or loosen these nuts.
Slide the flat steel bar through the bottom of the supplied poly bump stop and place it on top of the spring and over the mounting block.
place the other flat bar through the opening in the mounting block and bolt the 2 flat bars together with the bolts provided so that the mounting block, spring, and bump stop are all held together.
Check final alignments. NOTE: The springs do not have to be centered on mounting block over axle. Position springs to provide rear rollers with 3/4" forward clearance from any obstacles. Recheck that no brake lines etc. will be interfered with by the vertical travel of the springs.
Repeat the process on the other side. According to the instructions I had, there are some cases where the muffler hanger on the passenger side may interfere and they reccomend dropping the muffler hanger attachment bracket to the lower screw position where it ataches to the frame. I did not have this problem.
I have already added a leaf with my lift and was concerned that I would have a problem with the spring fitting but I had no problems. The only fitment issue I had was the metal wrap that holds the factory spring pack together in the rear wouldn't let me clamp down the rear part of the superspring all the way without really clamping down hard on the C-clamp. I finally got it down enough to get the bolt through and noticed no ill effects. Here is a before pic with a camper we borrowed that weighs approx. 4000 lbs. dry weight. Notice the sag and the fact that I couldn't lower the camper wheel stand enough to even get the wheel off the ground.
also with about 1200 lbs of gear in the trailer and the bed of my truck
And finally all folded up and with a weight distributing hitch (which helps a ton!)
Overall I am happy with the SuperSprings, they do stiffen the ride a good bit when not carrying a load but they also helped with the sag and sway when towing a heavier load. I thought about air bags but I have read that they can limit upward travel when going offroad. I'm not sure how these would be offroad, they seem really stiff and I think it would be a pretty hard ride going over bumpy terrain. Anyway...if your looking for something to help you carry a heavier load without bottoming out I would reccomend these.