When I did that work to mine plus the head gasket it was real rough until the computer finished relearning. Battery had been disconnected for a while and it seemed to take about a week to smooth out. I did use the Prothane race inserts though and thought that was the cause of the vibration but it settled down to just a little rougher than factory. I would also check the upper mount to make sure it is adjusted properly, can't remember the measurement off hand though.