^ This. Also, the stock rubber tranny mount could have ripped. I had that happen once. Double check all your motor mount bolts too, both into the mount to frame, and the mount to block. It is pretty common to break a motor mount at the block. I sheared a bolt, and broke out a piece of the block housing around another bolt. Then the third bolt fell out(or any other combo of failure) and I was left with a floppy motor.