My '97 C1500 has got a strange issue where the drivers side rear corner rides exactly one inch lower than the passenger side. The front end sits level. Got under it and looked today and I can't see anything that looks obviously broken or out of place, but to be honest I'm not really sure what to be looking for. Pretty sure it's not a body/frame tweak issue as the truck has been in the family since it was new. The leaf springs and shocks are all factory, I've never messed with them. Truck has about 130k on it. Any suggestions on what I should be looking for to fix this?