poly motor mounts

I put a poly tranny mount on my last Camaro... it shook pretty good for about 500 miles and seemed to calm down after that. There was a significant increase in interior noise from that point forward. Wouldn't do it on a DD again, but as a weekend/fun car it'd be tollerable. Certainly made the car feel more solid in shifting. Other than that I didn't notice any extra power to the wheels from the slightly reduced drivetrain loss. I'd bet it helped me put a couple more HP down on the dyno.
 
I liked the added solidity of the drivetrain, and since the car had a big cam, it made the cam lope more "tactile", as in you could feel the rock of the car more at idle... that was cool. The aspect I did not like was the added interior resonance.