How to Set the Timing on a Ford 390by Robert Bayly
The Ford 390-cubic-inch V-8 engine was produced from 1961 to 1976. It is a member of the "FE" series of engines that began with the 331-cubic-inch engine in 1958. The last engine in this series was the famous 428 Cobra-Jet. The 390 engine was found in full-size passenger cars and trucks. It was also available in some Mustang GT and GTA models. Proper engine timing on the 390 is necessary for optimum performance.
Park the Ford on a firm, level surface and set the parking brake. Run the engine until it reaches normal operating temperature. Turn off the engine.
Find the timing marker bolted to the timing chain cover on the passenger's side of the engine, just above the harmonic balancer. Slowly rotate the engine clockwise using a ratchet socket on the large bolt in the center of the crankshaft. Rotate the engine until you can see the numbers "12-9-6-3-0-3" stamped on the harmonic balancer. The numbers 12 through 3 represent the timing marks "Before Top Dead Center." This is the area on the balancer were you will set the timing. Wipe the balancer with a shop rag and paint the numbers with some white-out to make them easier to see.
Use a wrench to loosen the distributor hold-down bolt. Loosen it only enough so that you can barely turn the distributor. If the bolt is too loose the distributor will turn by itself when you start the engine.
Disconnect the vacuum advance hose from the distributor. Plug the hose with the end of a pencil.
Attach an inductive timing light to the engine by clipping the inductive lead over the number one spark plug wire. The number one spark plug wire is the first one on the passenger side of the engine. Clip the red lead to the positive battery terminal. Clip the black lead to the negative battery terminal.
Look for a decal in the engine compartment that gives the timing specification in degrees before top dead center. If no decal is present, you will need to find the timing value for your specific gear and make of Ford. A common setting for the Ford 390 is 6° before top dead center.
Start the engine and shine the timing light down at the timing marker. The flashing timing light will make the numbers on the balancer appear to be stationary. If the number on the balancer that is aligned with the marker is not within specification, turn the distributor until the proper number is lined up with the timing marker.
Tighten the distributor hold-down bolt. Recheck the timing to make sure it hasn't changed. Turn off the engine. Remove the timing light. Reconnect the vacuum advance line to the distributor.
- Be aware of moving belts, pulleys and the fan blade when using the timing light, because the light will make these components appear to be stationary.