When is it time to replace the leaf springs?

[cadillac_al]

I would only replace them if they wouldn't hold my normal loads. On my old 79, if 3 guys sat on the tailgate the rear bumper would almost hit the ground. If we had to ride over a ditch a couple guys would have to get off the tailgate. It sure rode nice though when it was empty. Soft is nice unless it won't carry the load you need to.