These Autolite Revolution HT spark plugs are designed to provide more space for additional intake valve and unobstructed intake ports. They will enhance power and create more efficient airflow without increasing the engine's size. The Revolution HT spark plugs from Autolite feature a 10mm high-thread design that can maintain the same dielectric, mechanical, and durability characteristics associated with conventional 14mm spark plugs. When doing a tuneup on your engine, use these Autolite Revolution HT spark plugs to get the job done.