Dude, you should get the air bags, then. All of my HDs have had overload leaf contact at about 1" from the jounce bumper. I have never had the springs settle in, or sag like you mentioned, though.
On the 4 newer service trucks we have, he had to add RideRites to keep them off the jounce bumpers with the weight of the service bodies, those things will loosen your spleen bouncing off those things all day
On the 4 newer service trucks we have, he had to add RideRites to keep them off the jounce bumpers with the weight of the service bodies, those things will loosen your spleen bouncing off those things all day

