how often do rear coil springs go bad?

[64stpside]

Originally Posted by jayoldschool

These things are bouncy with no weight in them. That's the price you pay for driving a truck. Throw 500lbs in the back, it will ride great. Mine has old springs, new shocks, good used trailing arms with good bushings. Bouncy when empty, great with a load.

I'm concerned about getting it on the interstate with it like that. I still got to check to see what shocks I bought. The thing is, I don't know what "this is as good as you can get it" is with the stk suspension. What does that feel like?
Thanks for everyone's help so far...