When it comes to optimizing your engine’s performance, the right components make all the difference. The Manley 5/16in Lash Caps are designed specifically for your high-performance needs, ensuring that your vehicle runs smoothly and efficiently.
The Manley 42139-8 Lash Caps are crafted from durable 4140 alloy steel, ensuring longevity and resilience under high-stress conditions. Their unique heat treatment process strengthens the caps, providing a hardness rating of HRc 50-54. This durability means you can push your engine to its limits without worrying about wear and tear. Plus, the non-rotating design helps reduce valve tip erosion, which translates to less frequent replacements and maintenance.
These lash caps are compatible with a variety of engines, making them a versatile choice for those looking to enhance their vehicle's engine performance. If you're working on a specific build, make sure to verify that your engine setup aligns with the specifications of the Manley 42139-8 lash caps.
Feedback from users highlights the reliability and performance of the Manley 42139-8 Lash Caps. Many have noted a significant improvement in engine operation following their installation. Users appreciate the quality construction and the peace of mind that comes with using a trusted brand like Manley. Here are some highlights from customer experiences:
Choosing Manley means investing in quality and performance. The 42139-8 lash caps are engineered to withstand the rigors of high-performance engines, ensuring that your vehicle operates at its best. Whether you're a professional mechanic or a DIY enthusiast, these lash caps are a smart addition to your engine build.
Upgrade your engine's reliability and performance with the Manley 5/16in Lash Caps today!
⚠ 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.