How do I set/adjust the timing? on 1990 Ford F-250

I've got number 1 piston to the top, distributor arm is at number one spark plug, but the timing mark is still off. Engine is lacking power (too retarded). Any suggestions?

1 answer
Unplug the SPOUT connector and set the timing to 10 degrees, Do this after the engine is warmed up and at a normal idle speed. The SPOUT connector is a little 2 wire black or gray connector that rests near the distributor. It disables the computer controlled timing so you can adjust it accurately.