1994 Toyota Corolla vibration, parked or moving

Hey folks, there seems to be a harmonic imbalance the engine has that affects the whole car, the timing belt was replaced @ 80,000 miles, (3,000 miles before I got it), is there a possibility that although the engine performs ok that perhaps they got the belt off a tooth? It has power but is not the little rocket ship that these things usually are.I've tried many things, engine mounts are ok, struts have all been replaced, what else is there. Love to hear what you've got to say. Thanks