DSS Racing Gen III FX Series Forged Flat Top Piston Set

Fits Most Chrysler / Dodge / Jeep / Ram 6.1L SRT8 Models

1-6840-4065 / 2-6840-4065 / 3-6840-4065 / K1-6840-4065 / K2-6840-4065 / K3-6840-4065

Overview:

The DSS Racing Gen III FX Series Forged Flat Top Piston Set is engineered specifically for the 6.1L SRT8 engines found in many Chrysler, Dodge, Jeep, and Ram vehicles. Designed to handle the demands of high-performance applications, these pistons offer a perfect balance of strength, durability, and precision fitment. Whether you are rebuilding your engine or upgrading for enhanced reliability and power, this piston set delivers consistent performance and longevity under extreme conditions.

Ideal for enthusiasts and professional builders alike, these pistons support high compression ratios and are compatible with various combustion chamber sizes, making them versatile for different tuning setups. The flat top design optimizes combustion efficiency and helps maintain a stable compression ratio, contributing to improved throttle response and power delivery.

Key Features:

Built to exacting standards, the DSS Racing Gen III FX Series pistons incorporate advanced design elements and materials to ensure superior performance:

• Compatible with 371 Small Block Mopar Hemi Gen III engines
• Flat top piston design with -1.5cc volume for optimized combustion
• Compression height of 1.21 inches for precise deck clearance
• .927 inch wrist pin diameter, available in full-floating or press-fit configurations
• Ring groove dimensions: 1.2mm top and second rings, 3mm oil ring for effective sealing
• Designed for a 3.578 inch stroke and 6.243 inch connecting rod length
• Supports approximate compression ratios ranging from 8.95:1 to 11.06:1 depending on combustion chamber size (65cc, 74cc, 85cc)
• Forged construction for enhanced strength and durability under high stress

Construction & Design:

These pistons are crafted from high-grade forged aluminum alloy, providing an excellent strength-to-weight ratio that withstands the rigors of high-performance and forced induction applications. The forging process refines the grain structure of the metal, resulting in superior toughness and resistance to cracking or deformation under extreme heat and pressure.

The flat top design reduces the risk of detonation while maintaining efficient combustion chamber dynamics. Precision machining ensures tight tolerances for optimal piston-to-cylinder wall clearance, reducing friction and wear. The option for full-floating or press-fit wrist pins allows customization based on engine build preferences and durability requirements.

Installation & Fitment:

The DSS Racing Gen III FX Series pistons are designed as direct replacements for the 6.1L SRT8 engines used in Chrysler, Dodge, Jeep, and Ram vehicles, ensuring straightforward installation with minimal modifications. Proper ring end gap and piston pin fitment should be verified during assembly to guarantee optimal performance and longevity.

These pistons are compatible with standard 3.578 inch stroke crankshafts and 6.243 inch connecting rods, matching factory dimensions for seamless integration. Whether performing a rebuild or an upgrade, these pistons provide a reliable foundation for high-performance engine builds.

What's Included:

• Set of forged flat top pistons (quantity as required for engine)
• Wrist pins (full-floating or press-fit options depending on SKU)
• Piston rings with specified groove dimensions
• Installation instructions and technical specifications

Ideal For:

This piston set is perfect for performance enthusiasts, engine builders, and racers seeking durable, high-quality pistons for their 6.1L SRT8 Mopar engines. It suits naturally aspirated and forced induction builds aiming for improved power, reliability, and efficiency. Whether upgrading a street car or building a track-ready machine, these pistons deliver dependable performance under demanding conditions.

DSS Racing — Founded in 1983 originally as Danny’s Speed Shop, DSS Racing has grown from a small Midwest performance engine shop into a respected name in forged engine components for the high-performance and racing markets. Based in St. Charles, Illinois, DSS is best known for its forged pistons and machined engine parts made in the USA that have been used in championship engines and thousands of builds, blending old-school racing roots with precision manufacturing for enthusiasts and racers alike.