BOB, YOU DIDN'T INDICATE IF YOUR CAR HAD A NORTHSTAR OR 4.9L PUSH ROD ENGINE. IF YOU HAVE A 4.9L ENGINE, IAN'S COMMENT STILL APPLIES. CHECK THE ENGINE AND TRANSMISSION MOUNTS ON THE FORWARD SIDE OF THE ENGINE. THESE MOUNTS GO INTO TENSION DURING ACCELLERATION WHICH IN TIME SEPARATES THE RUBBER FROM THE METAL PARTS OF THE MOUNTS.-----------PFI