I have a dumb question, Is there some kind of measurement to check the spring sag on the 99 3500 IFS 2WD Duals? I got this pickup from my brother and it led a pretty heavy life with utility boxes, tools and anything else he could pile in and has 300K on the clock. It now has a standard bed running empty but seems rather low on the front

 

The heavier trucks WILL sit higher in the rear.... 4 to 6 inches isn't unusual, is it worse than that??

 

Well I don't really know what the stock height or spring length should be in a stock situation. It does have overloads on the rear but it is not sitting on them, and I know coils can loose their strength. Thanks

 

I don't know if there actually IS a spec for that. You can grab the FSM for your truck from here, and go diggin'.