Red Cap Large

The ALLSTAR PERFORMANCE Red Cap Large (ALL 99367) is a universal screw-in filler cap engineered for cooling system applications across a wide range of automotive and small engine platforms. Constructed from aluminum with red anodized finish, this 3.000-inch OD cap delivers reliable sealing performance while the bright red coating provides high visibility and corrosion resistance in engine bay environments.

The 3.000-inch outer diameter accommodates most large-capacity radiator and overflow tank openings found on performance engines, late-model trucks, and heavy-duty applications. Aluminum construction combined with anodized finish resists oxidation and extends service life in high-temperature, high-vibration environments. The screw-in design ensures positive thread engagement and prevents accidental separation during operation or maintenance procedures.

This cap is ideal for engine builders, performance shops, and technicians who need a universal replacement for oversized cooling system openings where original caps no longer fit or seal effectively. The red anodized finish makes it easy to locate in the engine bay during fluid checks or service intervals, reducing the risk of leaving the cap off during operation. Weighing just 0.51 lbs, it adds minimal mass while providing durable, long-term reliability.

ALLSTAR PERFORMANCE is a recognized supplier of cooling system components and engine dress-up parts trusted by professional builders and enthusiasts. This universal design fits as an OEM replacement or upgrade wherever standard caps fall short on larger openings.