If you're looking to upgrade your vehicle's exhaust system, the Manley Valve - Exhaust, Valve-GEN II .3125 STEM is a fantastic choice. Designed with precision and performance in mind, this valve is engineered to fit a variety of automotive applications, ensuring that your engine runs smoothly and efficiently.
This exhaust valve is designed to enhance the flow of exhaust gases, which can lead to improved engine performance. With a precise stem diameter of 0.3125 inches, it fits snugly into the valve guide, ensuring optimal sealing and reduced wear. The custom specifications allow for a tailored fit, making it suitable for various domestic vehicles.
The Manley Valve - Exhaust, Valve-GEN II .3125 STEM is a universal fitment product, making it compatible with a wide range of vehicles. However, it is advisable to conduct thorough research to confirm that this valve is the right choice for your specific engine application. This diligence will help ensure a perfect fit and optimal performance.
Customers have praised the Manley Valve for its durability and performance enhancements. Many have noted that after installation, they experienced noticeable improvements in throttle response and overall engine efficiency. The custom design has been particularly appreciated, allowing for a perfect fit in various setups.
This product may contain chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. Please refer to the product documentation for more details.
⚠ WARNING:
Cancer and Reproductive Harm
https://www.P65Warnings.ca.gov

Manley Performance, formerly called Manley Speed Equipment, was established in 1966 by Hank Manley shortly after his graduation from Brown University. His interest in the performance and racing traced back to 1960 when, at age 17, he rebuilt a 312 CID Ford V8 engine, installed a camshaft and three two-barrel carbs, and raced a ’56 Thunderbird on New Jersey’s streets. Initially, the company’s product lineup included stainless valves, lifters, camshafts, forged pistons, vanadium valve springs, pushrods, and timing chain kits. By 1998, Manley had outgrown its first Bloomfield, New Jersey facility and bought several acres in Lakewood, New Jersey. It was around this time that the brand’s name formally changed to Manley Performance. Nearly a decade later, the production space doubled in size.
Evolving in the Automotive SpaceLed by GM Michael Tokarchik in 2002, Manley entered the high-performance passenger car market as an OEM supplier of connecting rods for the 2003/2004 Ford SVT Mustang Cobra. Production reached 2500 rods per week without missing a single delivery date. Ford awarded Manley its highest ever supplier rating. Manley’s presence in the OEM market continued from there as a supplier for the Ford GT. After nearly 50 years since its inception, Manley continues to be globally recognized as the leading manufacturer of performance valves, connecting rods, cylinder head components, pushrods, drive and oil systems, and several other engine parts.
What is Manley’s Specialty?Manley Performance specializes in high-performance engine internals that range from stock replacements to full-on race applications. They have been the standard of the industry since their inception; a fact that still remains true now as they have ventured into new markets. Today, Manley Performance continues to re-define itself in a high-performance aftermarket industry that is constantly evolving. The brand has developed a wide range of new products for growing markets that include sport compact, Ford modular, and Chevy LS. Manley also maintains its leadership role with the traditional V8 engine business.
Get Manley Performance at Vivid RacingIf you are in need of a serious upgrade to your engine, then Manley Performance parts should be on your list. Like all of our suggested manufacturers, Manley uses the best materials available to ensure a quality part for your engine. We carry Manley connecting rods, crankshafts, pistons, and valve components. The large lineup of domestic parts includes sport compact vehicles, Ford modular engines, GM’s LS series internals, and HEMI product upgrades for Chrysler.
If you can’t find what you’re looking for or need help choosing the right part for your car, call our sales team at (480) 966-3040. We are here to make your buying experience a breeze.