Theres a few schools of thought. 1) start the car and attach a vacuum guage under the throttle plates. when you find the highest vacuum, your there. 2) turn the distributor till you hear what you like from the motor. But this is best done when you know the car.3) timing gun. Set it to the specs and then, if you are running a few mods(coil, heads, intake ect) adjust a few degrees = or -. otherwise leave it to stock. Also, there is another theory but i havent tried this one yet. 4) set a glass of water about 1/2 full on your ain filter cover. turn till it either stops shaking or shakes the least. However, i have issues with water+engine. But, feel free.