Transmission Lifting

[tf95ZR1]

A few weeks ago I posted how under hard acceleration my gear shift lifts as much as 1.5". The motor isn't hitting the hood, so I didn't think it was the motor mounts. I put the car on jacks and tried to tighten the (2) front and (2) rear C-beam bolts. They seemed tight. I have had the C4 Beam Plates by Bill Boudreau on for about 3 years, no probs- I think they are great.
I gave up and took the car to my Chev dealer who I "kinda" trust. At first they said everything looked good: bolts were tight, motor mounts looked good, and to not worry about it. I didn't settle for this and after seeing the rear of the engine and trans lift under load, they put it up on a lift. Although they were tight, they still thought the movement was at the c beam bolts, and they tightened the bejesus out of them. We're talking basically breaker bar tight.
PROBLEM SOLVED, NO LIFT OR MOVEMENT now.
(Finally) the question- I remember reading that overtorquing can damage the rear of the trans. Yet this fixed the problem. Any suggestions? TIA

Ted

[95ZR1#418]

I guess without knowing what the actual torque to the bolts is now it's hard to say whats up. The simple explaination is you didn't have them fully torqued down after installing the beam plates.