Polished Aluminum Bung and Oil Cap

• Screw-in polished aluminum cap seals crankcase ventilation openings

• Built-in O-ring seats at the base for a leak-resistant, tool-free seal

• Fits 1 1/4" neck openings with 2"–2 1/4" base on universal valve covers

Polished finish dresses up Chevy, Ford, and GM engine bays

This polished aluminum bung and cap seals a 1 1/4" neck opening on universal valve cover breather, PCV, and crankcase ventilation setups. The screw-in design threads into a matching bung, and the included O-ring seats against the base for a leak-resistant fit. The base spans 2" to 2 1/4" to match compatible valve cover openings.

Built for hot rod, muscle car, truck, and performance engine builds, this cap finishes off the valve cover with a clean, polished look while supporting proper crankcase pressure control. It's a common fit on Chevrolet, Ford, and GM engine builds using a matching valve cover opening size.

Hardware is not included. Confirm neck diameter, base diameter, and attachment style (screw-in vs. push-in vs. grommet) against your valve cover before ordering.

Applications
Fits universal valve cover breather, PCV, and crankcase ventilation setups on hot rod, muscle car, and truck engines. Commonly used on Chevrolet, Ford, Mopar, and GM builds with a matching 1 1/4" neck opening.

Installation
Threads into a screw-in bung on the valve cover; the included O-ring compresses against the 2"–2 1/4" base for the seal. No mounting hardware is included, so hand-thread until the O-ring seats evenly.

What size valve cover opening does this cap fit?
It fits a 1 1/4" neck/bung inner diameter with a 2" to 2 1/4" base diameter, matching universal screw-in valve cover openings.

Does this cap include mounting hardware?
No. It threads directly onto a screw-in bung and seals with the included O-ring — no separate hardware is needed or included.

Is an O-ring included?
Yes, an O-ring is included and seats against the base for a leak-resistant seal at the valve cover.

Will this fit a push-in or grommet-style valve cover opening?
This cap uses screw-in attachment. Push-in or grommet-style openings need a cap built for that attachment type instead.

What vehicles commonly use this cap?
It's commonly used on Chevrolet, Ford, Mopar, and GM engine builds with a matching valve cover opening, plus hot rod, muscle car, and truck applications.

Does this cap affect crankcase ventilation performance?
Yes — it's designed to maintain proper airflow and pressure control for PCV and crankcase ventilation systems when matched to the correct opening size.

What clearance should I check before installing?
Check rocker arm, coil, hood, and breather clearance, since cap height can affect fit in tighter engine bays.