Launch Shudder? As in you're drag racing this panel?
Unless you're working it real hard I bet there are easier ways to solve the problem. Do you know why it shudders?
Since the turbo 350 was not stock I'd check the pinion angle, transmission mount, drive shaft length and balance. Center bearing and carrier.
Lots of things could cause the shudder, and unless the problem is the driveshaft itself or the center bearing that would be removed in the process changing to a one-piece won't solve the problem.
