Upgrade your valve train with Kibblewhite Valve Spring Lower Collars. These collars are engineered for superior performance and durability, ensuring optimal valve spring function in high-performance engines. Designed and manufactured in the USA, these collars are a testament to quality and precision. Description Kibblewhite Valve Spring Lower Collars are expertly crafted from heat-treated steel to provide exceptional strength and longevity. The precise machining ensures a perfect fit with 0.725" outer diameter seals and 0.565" valve guides. The counter-bored design enhances retainer-to-seal clearance, preventing interference and maximizing valve lift. These collars are ideal for both exhaust and intake valves, providing a reliable and consistent platform for your valve springs. Upgrade to Kibblewhite and experience the difference in valve train performance and reliability. Sold as a set of 4. Features & highlights Constructed from high-strength, heat-treated steel for maximum durability. Precision machined to fit 0.725" OD seals and 0.565" valve guides for a perfect fit. Counter-bored design increases retainer-to-seal clearance, optimizing valve lift and preventing interference. Suitable for both exhaust and intake valve applications. Proudly made in the USA, ensuring top-quality materials and manufacturing. Enhances valve train stability and performance, especially in high-RPM applications. Technical specifications Brand: Kibblewhite Material: Steel Collar Material: Steel Inside Diameter: 0.725" Application: Exhaust, Intake Type: Valve Spring Collar Units: Set of 4 Important to know No additional hardware is included with this set. Please ensure compatibility with your specific engine and valve train components before installation.