My truck on a daily basis probably has about 500lb in the bed (winch, toolbox, tools, bedmat, and bed cover). My truck was sitting perfectly level with just the bed loaded, which is probably 1.5" of squat without a trailer. I added the 2" block to get me somewhere close to factory specs, and I also tow a 5,000lb travel trailer (with a weight distribution hitch) around during the summer. My axle isn't overloaded, it's just that these factory springs seem a lot softer than previous gen trucks. No one makes a Add-a-leaf for our model trucks yet, I looked into it. Which led me to my current adventure, trying to find NHT rear leaf packs. I'm okay with some squat while towing, but I wasn't okay sitting level unloaded.