However, the number "1" on the distributor cap itself doesn't directly correspond to cylinder #1. The location of the #1 spark plug wire on the distributor cap depends on the distributor's orientation and the particular year and even the specific distributor used on your 390.
To find the correct wire placement:
1. Identify Cylinder #1: Locate cylinder #1. This is typically the front-most passenger side cylinder. Consult a shop manual or online resources specific to your 390 FE engine to confirm its exact location.
2. Rotate the Engine: Turn the engine by hand (using a wrench on the crankshaft pulley) until the #1 piston is at Top Dead Center (TDC) on the compression stroke. You'll need to check for this using the timing marks on the crankshaft pulley and the timing pointer. Again, consult a repair manual for precise details on your engine's timing marks.
3. Distributor Rotor Position: Once #1 piston is at TDC on the compression stroke, observe the position of the distributor rotor. The rotor should be pointing towards the distributor cap terminal that corresponds to the #1 spark plug wire.
4. Follow the Firing Order: Once you've found the #1 wire location, follow the firing order (1-5-4-2-6-3-7-8) to place the remaining wires. Each subsequent number in the firing order should connect to the next terminal clockwise (or counterclockwise, depending on your distributor's rotation) around the cap.
Important Note: A repair manual specific to your year and model of Ford 390 FE is crucial for this process. Incorrect spark plug wire placement can cause serious engine damage. If you're not comfortable performing this task yourself, seek the assistance of a qualified mechanic.
