Where is number one on the distributer cap of a 1990 305 Chevy silverado?

The number 1 cylinder location on a distributor cap for a 1990 305 Chevy Silverado is usually in the front right, looking at the engine from the driver's seat. However, this is not guaranteed. The firing order of the engine dictates the cylinder placement on the cap, and there's a chance a shop or previous owner may have incorrectly installed components.

To be certain:

1. Consult your owner's manual: It should show a diagram of the distributor cap and firing order.

2. Check a reliable online resource: Websites specializing in automotive repair information (like Haynes or Chilton manuals online) often have detailed diagrams for specific vehicle years and engine types. Searching for "1990 Chevy Silverado 305 firing order" will be helpful.

3. Trace the wires: Carefully follow the spark plug wires from the distributor cap to the spark plugs themselves. The wire from the #1 cylinder location will go to the #1 spark plug.

Using the firing order diagram and the physical placement of the spark plugs, you can pinpoint #1 on the distributor cap with certainty. Avoid relying solely on assumptions.