These Vintage NOS AC Delco Professional spark plugs are the perfect choice for your engine. With its OE/OEM part number of 5613957 and manufacturer part number of R45TS, you can trust that it will provide optimal performance for your vehicle. Measuring at 3 in. in length, this spark plug is a vintage and performance part that is made in the United States. Lot of 7 spark plugs, see pics