One of the next upgrades on my short list is the rear suspension, I just put new Edelbrock IAS shocks on but I frequently tow "gently" ;-) over the weight limit for my truck. Ok more frequently than gently. But anyway I have been considering helper springs or airbags, the airbags have obviously the most "cool factor points" and seem to be function and fairly cheap.
Anybody tried either? I don't want the truck to bounce up and down or dance or anything but I would like to level out my plane with the big trailer on it.