Funny Story: stupid on my part. After finishing the completion of my cobra, if you really ever can
, I took the car to the tuner to set up the 427 TWM injection. didn't bother doing a run through of the rear suspension. Tuning went great, drove it home but get hearing a clanging noise when i hit bumps. you guessed it, the drive shaft was hitting one of my chrome oly driveshaft loops. I ended up really doing a number to both, but after setting the pinion angle I was good to go. I never noticed any vibration or anything odd from my stupid oversight but was thinking about fixing/replacing the driveshaft and chrome oly loop.
Your guys recommendation. Keep the same driveshaft and have it balanced, get an new one (what material) and have it balanced.