DELCO REMY 6 CYLINDER NOS DISTRIBUTOR WITH CAP Dual Plugs | eBay
Museum of American Speed - Check out this 1934 Morton & Brett head for Modal A block. It features a two-port intake with 2 spark plugs per cylinder. | Facebook
Why Do Aircraft Engines Have Two Spark Plugs Per Cylinder? | Boldmethod
Why do some gasoline engines have 2 spark plugs per cylinder? - Quora
Why do some gasoline engines have 2 spark plugs per cylinder? - Quora
Why do some engines have 2 spark plugs per cylinder? - Quora
Answers to Frequently Asked Questions About Spark Plugs
Dual ignition - Wikipedia
Two spark plugs per cylinder...good or bad? - Harley Davidson Forums
Dual ignition - Wikipedia
2 Spark plugs per cylinder 2004 - 2013 Dodge 5.7L V8 $ for tuneup spark plug replacement - YouTube