I am trying to resurrect my poor 83 Z from the dead. I bought it with a broken rear end last summer. I finally drove it after enormous amounts of work and when I shift (5 speed) it has a mean vibration. Is it that my flywheel is shot or needs to be run a while ( car sat forever ), or could it be that I need one of two rubber bushings that is not on the tranny crossmember that should be?Please *** help me before I sink this car in the local pond!!

 

probably does need those mounts

check the drive shaft at a local drive shaft shop ( Balancing) only after Taking the shaft out and turning the rearend pinion to the oposite side.
Dude so much crap can make your car vibrate it isn't even funny!
DON"T SINK IT THOUGH, Sell it to some unsuspecting kid and let his youth be But seriously you didn't mention if it was going down the road when this happend. Whatever your answer is I think I can help.

 

Reread your post !!!!!!!!!!!!!

Do you realize at what angle you are making that rearend sit at WITHOUT The buhing on the cross-member