I have a 1966 Mustang, drove great before I got an oil change. After the oil was change I started the car and it shook real bad. I got to a light and then it stalled. If I put it in reverse it stalls. I checked the filter- its on tight, the spark plugs, the alternator, carb, points- my car still has points not electric ignition, and wires with a wire tester. The engine acts like it being pulled down. I just can't think of what it is. Any help would be great!!!