I wouldn't buy a suspension kit from eBay. Reason being that the eBay kits don't usually list part numbers or manufacturers, so it will be nearly impossible to confirm what parts you're actually getting until they arrive. With the age of these cars there's no guarantee that buying a kit for your particular year will get you all the right parts, things may have been swapped out along the way.
PST has great quality parts and is a FABO vender, so if you call them you can get a 10% discount. Plus, you can talk to someone about your specific car and confirm what you're actually going to get for parts. And on top of that, if you get something that doesn't fit they're easier to deal with on returns. Yes, it might cost more money, but IMO it's worth it for the support.
KYB has always made good quality gas shock and are reasonable. Have used them 40 plus years on E-bodies. Just another option for you.
This depends entirely on what you want out of your shocks and what torsion bars you run. The KYB gas-adjusts on my Challenger made it ride like a buckboard. Teeth rattling awfulness. Upgrading to a set of Bilsteins completely changed the ride quality of the car. You have to match your shocks capabilities to the spring rates of your torsion bars. KYB's might be ok for the horribly undersprung stock torsion bars, but start making upgrades and the KYB's will show their inadequacies. They're not what you want for torsion bars anywhere near 1" in diameter, and flat out the wrong choice for any torsion bars significantly over 1".
Shocks are relative to nothing more than ride quality.
Nothing could be further from the truth. This is 100% false, and if you believe that then your understanding of how suspension works is totally flawed. Your traction is controlled by how well your shocks work.
The reason suspension exists is to maintain tire contact with the road. It's there to maintain and improve traction, that is the primary goal of
all suspension. Yes, ride quality and comfort are an important side effect of this, but don't think for a second shocks are just there for ride quality, they are there for
traction. An undamped spring (no shocks) will continue to oscillate after a impact/load application. That means the load pressure on the tires oscillates too! In extreme cases that could mean losing tire contact with the road, although generally would it would mean is losing traction because the load on the tires would be oscillating, so you would gain and lose traction as pressure on the tires increased and decreased. That's underdamped oscillation. Most of us have experienced this driving around on worn out shocks- you hit a bump and the car keeps rocking even after the bump is in the rear view- that's underdamped. If you have shocks that are too stiff (like the KYB's with larger torsion bars!) the result is that the shocks limit suspension travel. That results in a overdamped system, which rattles your fillings out and can cause the tires to lose traction if they're bounced up off the road (impact is more than the travel can absorb in the amount of time needed). Ideally, you would have critically damped suspension, the shocks would match perfectly to the springs and as a load was applied the suspension would fully absorb the impact, but not oscillate any further.
Typically car shocks are slightly underdamped. You get a better ride quality out of them like this than if they're overdamped, and of course you're probably not going to perfectly match your shocks to your springs buying off the shelf components. So it's better to miss a little soft for the sake of ride quality. But you are sacrificing a little traction to do that. Not likely anything you'd actually notice though as long as you're close.
