transamls1woa

i installed a polyurethane transmission mount from f body motorsports in my 98 trans am a4 and since then i can feel a lot more vibration than before i installed it. Is that normal because of the harder material? It came with a spacer and i tried it with and without it vibrates the same either way. I have it in though cause they said use it. My friends say somethings wrong but i think it could be the harder mount causing you to feel vibrations. Does anyone know anything about it?