I am thinking about using a set of stock leaf springs on my 96 F350. The problem is they came out of a beat to hell donor truck and I am not sure if they are still good. I do have an add-a-leaf kit sitting on a shelf I am thinking about using with them. But how do I find out if they can still hold the weight of that Power Stroke? I do plan to strip them down to bare metal and look for cracks, but what else can I do to make sure they are still serviceable?