Automatic Transmission - transmission mount

all right ive found a few threads about the soft GM transmission mount but none have a solution so im going to start a new thread. ok it all started when i installed a umi torque arm. im not bashing UMI nor am i saying they have an inferior product. Quite the contrary i love my new torque arm. But since i put it on my car has gone downhill. First my car sounded like a jack hammer was coming through the floor board, which i soon discovered was a broken transmission mount. So i figured it was time for an upgrade. So i bought an Energy Suspension transmission mount. Now i ahve the same jack hammer sound under the floor shifter but only when i hit bumps in the road. then i cranked it up to go to work this morning and discovered i have a subtle vibration when it is in park. its comes and goes like clock work. Its like its good for 2 seconds then it vibrates, good for two seconds then it vibrates, and so on. And now i suddenly have a random misfire. Btw its a 1997 formula LT1 a4. Please help any suggetions would be gladly appreciated. thank you:usa:

maybe engine mounts are bad too???

No the jack hammer sound was the torque arm and the vibration was the poly trans mount...ling story short swapped back to the stock torque arm for now and changed the trans mount to a stock 4l80e mount. Which was a perfect fit. It's a little beefier then the soft 4l60e mount.

And the misfire was from my headers eating another spark plug wire...I got ovc wires now and no complaints so far