Ride Quality

[uwe]

Hi All,
My 1997 Suburban ( relatively new to me) rides very rough after i replced the original shocks with Bilstein HD units. My main gripe are short bumps like on a bad road, sending shudders and rattle throughout the entire vehicle. I run the stock 235/75/R15 LT Michelins.
Now, on a smooth, fast road, the ride is excellent, controlled and very tight.
Loading the vehicle or trailer towing does not affect the ride hardly at all, it stays bumpy and rough over bad roads, or road sections.
The real killer are California's concrete freeways, with mismatched expansion joints. It starts an oscillation with the trailer that can't be good in the long run, not for the truck, not for the Airstream.
Did I buy the wrong shocks, or are these trucks just that stiff?
Please share your experience with me.
My solutions are:
Softer shocks, velvet ride shackles, etc.
Please advise.
Uwe