The rear of my 04’ Ram 1500 sags quite bit when I hook up my 19ft travel trailer to the hitch….even with the load distribution bars being fully torqued down. I think some of the problem might be that my truck has been “leveled”, so the front sits a little higher than a stock truck…..witch makes the rear squat look that much worse. I’m sure some of the problem could just be that the rear springs are old, and worn out. I’m looking for some options to stiffen the rear suspension up a little bit when I’m towing my camper and boat. From what I’ve seen…I have a few options. Either an air bag kit, or some helper springs (firestone assist springs). Are there any other options I should look at? What’s the best option?