They are all an improvement over stock. I do not believe anyone has had trouble with any aftermarket driveshaft. American Muscle has one for under 700 and I believe there is another for around that price range but I cannot think of the name.
Yeah it's boiled down to one of three things:Blaseleblanc, since you have an auto, then yes it may be the driveshaft that is causing some vibration.
Since our DSs spin at higher speeds, you need to ensure they are designed with that in mind. There are only three companies that spin shafts up to 8,000 rpms: Precision Shaft, Driveshaft Shop, and Dynotech. Only DSS and Dynotech sell shafts for the 3.7.Not wanting to start a new thread, but interested in finding if anyone has dealt with Mark Williams driveshafts? Read an article where they talked about how they build their shafts, and it appears they also do work for NASCAR spec cars. It sounds like a good product and a street worthy shaft is decently priced.