I have just finished changing out my old auto tranny for a 5 speed, and it all works fine; However, when the car's rpms goes up the car starts to shake, the higher the rpm the more shaking. It also does this at startup... This ever happen to anyone or does anyone know what it could be from? Thanks

 

Inbalanced flywheel? What flywheel did you use?

 

I used the trans and all accessories out of an 86 firebird.... I did machine the flywheel to make sure it was flat... Any other ideas?