It would be worth talking to Rob at Delta Vee Motorsports in Kallamazoo Mich. He is one of the best versed with 348 and 355 Shocks around. He may be able to revalve your existing ones. Good luck, Bryan.
Yea, I am considering using him, but I was just wondering if there is a better aftermarket Shock out there instead of re-doing the existing shocks.
There are a few options but they are not cheap, Nitron, Moton, Öhlins... Depends on budget, taste and requirements.
It all depends on the cars intended use. Are you going to track the car or just drive it on the street. Is there a problem with the shocks currently....ie leaking?
What performance aspect are you trying to improve ? Which car are you trying to improve it upon? Also note: one of the reasons the rear end is soft is to avoid snap oversteer under power application.
One of them is starting to leak. Just like anything else in life, newer technology tends to be better than 21 yr old tech. So, I was looking to go with the newer tech. The re-build option requires my car to wait 6 weeks for turn around, so that's really not an option anymore.
I'd find some used ones on Ebay or something, send those out for rebuilding and then swap on your car. With rising values, it pays to keep the car oem looking and not use aftermarket parts which detract when selling.
If you had them rebuilt, you could specify a slightly thicker oil and get higher rebound and compression dampings. Slightly should be between 10% thicker and 15% thicker. Any more and you start needing different springs or you get the chassis reactions of an overdamped car.
Robs advice would still be best. The 355 CH used unmodified shocks. They used the std 355 rear shock at both ends with a revised Bilstien control unit.