solid, poly,or rubber mounts

i my have some engine, transmission, rearend miss alignment problems going on. i have changed everything myself. motor, tranny, rearend ect. i have the right harmonic balancer,weighted converter,and my drive shaft was just re- done by our best driveline shop in town who also shimmed my rear end(but never drove the car)...my car has always had a vibration even before my work. if you were to drive 65mph and let off the gas it would vibrate bad on and off while decelerating, w/a slight vibration at just above idle. i have had all four wheels aligned at a shop(the car drives straight no hands) how do i go about lining up my motor and trans to my rearend, or any ideas?(maybe now the car has insurance i should take it back to the driveline shop)ahhhhhhhhhhhhhhhhhhhhh i hate giving my keys over. :-|