I have a 2006F250 4x4 extened cab with a powerstroke diesel. I use it as a dailey driver and for two months a year I vacation with a 12200# 5th wheel. It has 90,000 miles on it and my question is 1. what are the life of the stock shocks under these driving conditions and 2. what would be the best replacement shocks for the truck. In the old days one could stand on the bumper and bounce the truck and if it keep bouncing you put on new shocks. At 200+ pounds I can't get it to bounce. But when cornering and you hit a little washboard it now hopps sideways. It was more pronounced after I installed new tires.