Thanks guys.
I'm not so worried about the springs themselves so much as about the rest of the suspension -- knuckle bearings, wheel bearings, mounts, etc.
I assume it's the shocks, not the springs. They are Ranchos up front and big fat yellow ones (Monroe??) with the name worn off in the back. It seems as if they hardly absorb anything, but I can live with the ride if it's not a matter of damaging things.
I am sure that stiffer shocks do more damage to the rest of the car -- Newton's second law and all that. But I don't know how much more damage they do. Will I wear steering knuckles and wheel bearings 1.000001 times as fast? twice as fast? What about the tires? Again, I'm pretty sure that I run a greater risk of bruising tires against the rocks, but how much greater?