I would scrub it with blue scotchbrite and look it over for any cracking, and have a shop look it over and balance it,and add new joints. You can use the flanges from the stocker. Thry're the only good part of the original one,lol.
As far as vibration goes, I really had issues with the stock one. Issues with the stock ones is why Jerry wrote an tech article about critical driveline speed. It's worth reading.
Here are some comments about driveline bending. Anything that is spinning has centrifugal force. We have all felt it with one thing or another. Well, so does a driveshaft. The driveshaft is fixed at each end (not really but I may touch on that later) and spins. An MN-12 driveshaft is about 57"...
forum.birdcats.com
Tires and shocks can cause vibration too, for a few reasons,
I found a tire that would not balance, however I tried. "road force balance "is the best, and does it on the car, doing the whole wheel assembly. They told me about the ds being bad, the wheel bent,and the yellow wheel stud being mismarked one one wheel,and fixed it. It' where the schrader valve goes.
I found there are 3 grades of tires, and Sams/walmart were the worst grade. Note, this is across all brands. Summit and tirerack sell the best grade only. I was buying BFG traction ta tires at the time, they discontinued those in the 00's. The 15yo maypops on the red cougar are the last set I could get.
It'll get new ones before it gets driven. I'm looking for sticky summer tires for it in 15's.
