Towing a 3500# trailer: shocks or air lift?

[97 Explorer EB]

I recently purchased a 17' travel trailer that weighs 3500# loaded. The Explorer is too low in the back. A mechanic recommended "airlift" but I can't find parts that fit my model (V8 Eddie Bauer AWD). Should I just go for shocks instead? If so, which ones? I don't do much off road, just highway. I want a smooth ride when not towing, but want to stay level when I am towing. For a vehicle that says it can tow 6000# it sure seems to be struggling with half that amount. It's like driving a sled. Thanks for your help!

 

[dogfriend]

A weight distributing hitch might work better for you to stay level when towing. It works by transferring more of the load to the front.

http://www.ehow.com/how_2094696_setup-weight-distributing-hitch.html

http://www.youtube.com/watch?v=d2WMeZy07Jg