Need Advice, Suggestions

don't presume they redid the ball and trunion part of the driveshaft the kit ain't exactly cheap

So what you are saying is if I remove the driveshaft completely out of the car and start it up and run it through 1st, 2nd, and drive and it does not shake or vibrate then it would be a driveshaft problem..correct??...sorry I am no mechanic as you guys have probably already figured out...