Part number 23320 is a polished billet aluminum oil fill cap designed to fit late-model GM valve covers with screw-in style openings. Machined from 6061-T6 aluminum, it features a knurled edge for easy hand tightening and removal, and uses a Buna-N O-ring to ensure a secure, leak-resistant seal. The cap has a 1-9⁄32"-8 thread.

• Application: Late GM valve covers with screw-in oil fill
• Material: 6061-T6 billet aluminum
• Finish: Polished
• Thread size: 1-9⁄32"-8 • Features: Knurled grip edge, leak-resistant, clean styling