I just installed the front prothane transmission mount on my ss/sc and it is just a little bit rough for my taste. Just a little. I was thinking this.

What about taking a 1/4 or slightly larger drill bit and drilling 2 or 4 holes around the center of the mount (centered between the edge and the bolt)? I know it would sacrifice a little stiffness, but would also ease up on the vibes?

 

I would not do that the vibes will go away after a few hundred miles on them but i would not drill them out my opinion man i have both front and rear and ttr motor mount and my vibes are gone after 2000 miles

 

That is what prothane did to the cavalier tranny bushings, was put about 6 holes 1/2" in diameter. Over time the center hole with the bushing/sleeve gets ovaled out in the bushing and the tranny has a lot of movement.

We designed our own bushing for the cavalier/sunfire now without those holes, and customers really like them.