Hi everyone, I am getting a bad vibration around 4000rpm every gear no matter what speed. Over the last two winters I had the engine and transmission and rear differential out of the car. The trans(st10) has been rebuilt and so has the rear diff. The engine is balanced and the rebuild is about five years old. here is what I've checked so far: replaced distributor with good spare(no change) re-set valve lash(no change) removed drive shaft and checked ( checked ok) I noticed trans mount bolts were loose, tightened them and vibration is now WORSE! Any thoughts?