How to Time a Ford 351by Robert Bayly
While technically considered a small block engine in the same family as the 289 and 302-cubic inch engines, the 351-cubic inch V-8 has a taller block, larger connecting rods and a larger crankshaft. The 351 also has a firing order of 1-3-7-2-6-5-4-8 as opposed to the standard 1-5-4-2-6-3-7-8 Ford V-8 engines. The 351 was produced from 1969 until 2001, but complete engines can still be purchased. Engine timing is accomplished in the same manner as any Ford V-8 engine.
Locate the timing pointer attached to the timing chain cover, below the water pump on the passenger's side of the engine. The pointer sits about 1/2-inch above the harmonic balancer. Wipe it off with a shop rag.
Find the timing marks on the harmonic balancer. If you can't see them, bump the engine over with the starter until you can see them. The marks will read "BEFORE-30-20-10-0-10-AFTER," with small lines between the numbers. The lines represent an increment of 2 degrees. Wipe the marks off with a shop rag and mark them with liquid eraser to make them easier to see.
Disconnect the rubber vacuum advance hose from the distributor and plug it with a small screw.
Connect an inductive timing light by clipping the red lead to the positive battery cable and the black lead to the negative battery cable. Clip the inductive pickup on the timing light over the number one spark wire. The number one wire is the first one on the driver's side of the engine.
Use a wrench to loosen the distributor hold-down bolt. Loosen it just enough so that you can turn the distributor with some effort; otherwise, it will move by itself when you start the engine.
Start the engine and shine the timing light down onto the timing pointer and balancer. Be careful of moving belts and the fan. The timing light will flash, or strobe, with the firing of the number one spark plug. It will make the balancer appear to be stationary. Read the number that is lined up with the timing marker. The timing specification varies slightly for different years, but the most common setting is "10-BEFORE." If adjustment is needed, turn the distributor until the 10-BEFORE is lined up with the timing marker. Your engine may have a sticker on it that states the timing specification.
Tighten the distributor hold-down bolt. Recheck the timing. Turn off the engine. Remove the timing light. Reconnect the vacuum advance hose to the distributor. Test-drive the vehicle. If it clatters or pings when you accelerate, hook the timing light back up and move the timing down to "Eight-BEFORE." Test-drive again. If it still pings, move to "Six-BEFORE."