Shaker 3.8 mustang

I have a 1994 ford mustang with a 3.8 liter V6. The engine ran hot on me as a result of a stuck T-stat. Now ever since over heating the engine has developed a vibration that comes around 1500 RPM. it is felt in gear and out of gear. I have tried a know good front balancer and removed the transmission to inspected the flywheel weight. all appear to be good. I have inpected the engine mount as well to no avail. please let me know your thoughts

Have you done a compression test? Assuming the vibration is actually related to the overheating, the most likely answer is that you lost a cylinder due to a head gasket or burnt valve.

Make sure you didn’t melt any spark plug wires too.