from
https://www.sdtrucksprings.com/timbren-vs-air-bags
Which is better?
Both the Timbren Suspension Enhancement System and Air Bag Helper Springs are great products. Which is better would come down to user preference. If you are looking for full control over the product and the adjustability factor than Air Bags are the one to choose. If you want something that is lower maintenance and has that set it and forget it benefit than Timbrens will be the winner. Whichever product you decide to go with will be a great choice. Both will add additional load support, protect your current springs and improve loaded ride comfort.
I have airlift 1000HD. They are double the capability of the airlift 1000, and cheaper than the 5000. I dont have onboard air, I bring a bike pump with me.