Roadmaster Active Suspension

I had them on 3 different trucks including the one I have now. I like them. Reduce axle wrap full-time and rear-end sag when loaded. They don't affect unloaded ride of the truck but do make the rear end a little higher unloaded.
Easy enough to install....took me an afternoon but I am slow and very careful when a vehicle is up on jack stands! (And don't use Harbor Freight stands!!). You can sometimes find them on ebay (new) for a great price.