How do you set 4 degrees before top dead center?

Answer 1

Put a timing light on the number one spark plug wire. Start the engine and remove the vacuum advance hose from the distributor and plug the hose with something such as a screw. Loosen the hold down bolt on the distributor just enough where you can turn the distributor. Shine the timing light on the harmonic balancer and notice the mark in reference to the index mounted to the timing chain cover. It shows degrees before and after a center line which is Zero or top dead center. Rotate the distributor slightly in each direction, and notice how the timing mark moves on the index. Turning the distributor counter clock wise advances the timing. Clockwise retards it. When the line on the harmonic balancer is lined up with four marks advance on the index, tighten the distributor and you're done. Reconnect the vacuum hose and remove the timing light, and go.