I have just finished the swap on my 88 firebird from auto to a 5speed. I used a t5 out of an 85 bird w/ the flywheel from an 85 bird.... I had the flywheel cut and it is in balance, however when i start the car the car shakes like crazy. Any idea on what could be causing this situation? The machine shop said that the crank on the 85 and the 86 firebirds are different, so its possible that the flywheel is causing it. Anyone have any ideas? thanks

 

maybe one of the engines is internally balenced and one externally? that could cause a bad shake