I had a 93Z28 with a 383 and D1 Combo, It had a bad vibration after the motor install, which I never drove much then tore it apart.

I recently bought a 95Z28 with a bad T56, missing 2nd gear. Other than that, no real problems or vibrations. I swapped the T56 out of my 93Z28 into this 95, and now I have this horrible vibration, starting at 40 its vibrating the center console around, and it just gets worse, at 100 it feels like the cars coming apart. The car is lowered with Eibach Pro kit, stock driveshaft, LS1 rear end with LS1 brakes front and rear.

Its not the driveshaft as it wasnt vibrating like this till I swapped transmissions, still, I jacked the rear of the car up and pulled the rear tires off, and ran the car with no rims and tires, same vibration from 40 and up. shaking the car around.

I checked the Tailshaft bushing, and there is slight movement in the driveshaft where it goes into the back of the T56, wear in the tailshaft bushing is what Im guessing, but would this slight movement cause so much of a vibration in the car? It has to be in the transmission.

I forgot to mention, when this trans was in the 93 with the stroker, I twisted 3 LS1 Aluminum driveshafts in half, slamming them around under the car, Im wondering if this bent the mainshaft in the trans...

How hard would it be to swap the tailshaft section of the bad tranny to the new one? Is it something I could do without pulling the trans again?

Anywho, any help would be appreciated..

Thanks,
James