Suspension Restoration, How Much Improvement

[hancock1701]

My car currently has 140k miles, and as far as I know, the suspension is stock. I checked the suspension, all the bushings still seem fine, only the infamous clunking from the rear, so I'll replace those trailing arms soon.

Overall, the car drives fine. But I only know how it drives when it's already old, I don't know how it's supposed to drive when new. I've only had the car for the last 2 years and 20k miles.

So I'm looking to restore it back to original ride quality. My question is, how much improvement will I get if I install four new shocks? Like I said, it drives fine to me, no diving or rolling or dipping, no leaks. Is there another way to test the shocks without removing them? I see the bounce test wouldn't work with these heavy springs. But at that mileage, it's hard to believe those shocks are still good. Those shocks are expensive, so I want to be sure about this.