Manley Performance NexTek Hi-Perf Valve Spring Set

2011–2024 Chrysler 300, Dodge Challenger, Dodge Charger, Dodge Durango, Jeep Grand Cherokee SRT/SRT8, Jeep Wrangler, Ram 2500/3500, Jeep Grand Wagoneer 6.4L 392 HEMI

Part #: 221439-16

Overview

The Manley NexTek Series High Performance Valve Springs are precision-engineered for Chrysler’s 6.4L 392 HEMI engines, supporting valve lifts up to .650 inches. Designed for enthusiasts and professional engine builders alike, these springs enhance valvetrain stability and durability under demanding high-performance conditions. Whether upgrading for street driving, track competition, or serious racing, these springs deliver reliable valve control at elevated RPMs and aggressive camshaft profiles.

With Manley Performance’s commitment to quality and innovation, the NexTek springs provide consistent performance and longevity, making them an essential upgrade for maximizing the potential of your Chrysler 6.4L HEMI engine.

Key Features

Manley’s NexTek valve springs incorporate advanced materials and design features to optimize valvetrain function and reliability. Key highlights include:

• Specifically designed for Chrysler 6.4L 392 HEMI engines with valve lift capacity up to .650 inches
• Manufactured from premium spring steel for superior strength and fatigue resistance
• Precision wound to exact tolerances ensuring consistent spring rates and dependable valve control
• Single spring design optimized for aggressive camshafts and high RPM operation
• Engineered to reduce valve float and maintain valvetrain stability under extreme conditions
• Compatible with factory retainers and valve train components for easy installation
• Ideal for street, strip, and track applications requiring enhanced valvetrain performance

Construction & Design

Manley NexTek valve springs are crafted from high-quality spring steel alloys that undergo rigorous heat treatment processes to maximize durability and fatigue resistance. The tightly controlled winding process ensures uniform spring rates across all springs, providing consistent performance and reliable valve timing.

These springs are engineered to seamlessly integrate with the Chrysler 6.4L HEMI valvetrain geometry, supporting high valve lifts and aggressive cam profiles without compromising engine responsiveness or reliability. The robust construction helps maintain precise valve control even under the most demanding high-RPM conditions.

Installation & Fitment

The Manley NexTek valve springs are direct replacements for the factory springs on Chrysler 6.4L 392 HEMI engines from 2011 through 2024. They fit OEM valve train components and retainers, allowing for a straightforward installation without the need for cutting, drilling, or special tuning. This makes them an excellent upgrade for performance enthusiasts seeking to enhance their engine’s capabilities with minimal modification.

Compatible vehicles include:

• 2011–2024 Chrysler 300 6.4L 392
• 2011–2024 Dodge Challenger 6.4L 392
• 2011–2024 Dodge Charger 6.4L 392
• 2011–2024 Dodge Durango 6.4L 392
• 2011–2024 Jeep Grand Cherokee 6.4L SRT and SRT8
• 2011–2024 Jeep Wrangler 6.4L 392
• 2011–2024 Ram 2500 and 3500 6.4L 392
• 2021–2024 Jeep Grand Wagoneer 6.4L 392

What's Included

• Single Manley NexTek Series High Performance Valve Spring (SPRING-1.311 SINGLE)

Ideal For

• Performance enthusiasts upgrading Chrysler 6.4L HEMI engines for improved valvetrain stability
• Street and track drivers seeking enhanced valve control at higher RPMs
• Engine builders requiring reliable springs for high valve lift and aggressive camshaft profiles
• Racers and tuners pushing the limits of their 6.4L 392 HEMI engines with demanding valvetrain setups