Wiseco K398X7 Forged 4.070" LS Pistons -3.20 cc Flat-Top (Set of 8)

Vehicle Fitment

• GM LS-series V8 engines (Gen III / Gen IV, standard stroke)

Features

• Forged from high-strength 2618 aluminum for excellent durability
• ArmorGlide® skirt coating to reduce friction and improve wear resistance
• Flat-top crown design with -3.20 cc volume for moderate compression
• Precision ring grooves with anti-detonation and pressure-seal grooves
• Forced-pin oiling for consistent wrist pin lubrication
• 0.927" floating wrist pin for reliable high-RPM performance
• Designed for severe-duty performance builds (NA, nitrous, or moderate boost)
• Includes high-quality ring set (1.2 / 1.2 / 3.0 mm)

Specifications

• Bore Diameter: 4.070 in
• Stroke: 3.622 in
• Compression Height: 1.304 in
• Piston Volume: -3.20 cc (flat-top)
• Piston Material: Forged 2618 aluminum
• Wrist Pin Diameter: 0.927 in (floating)
• Rod Length Compatibility: 6.125 in (standard LS rod)
• Ring Groove Sizes: 1.2 mm / 1.2 mm / 3.0 mm

Included Components

• 8 x Forged pistons (K398X7)
• 8 x Floating wrist pins (0.927")
• 16 x Circlips / retainers
• 8 x Ring sets (1.2 / 1.2 / 3.0 mm)

Product Description

The Wiseco K398X7 is a professional-series forged piston kit tailored for GM LS V8 engines with standard stroke. Its 4.070" bore and -3.20 cc flat-top design provide a balanced compression ratio suitable for performance applications ranging from naturally aspirated to nitrous or mild forced induction.

Built from 2618 alloy, these pistons are exceptionally strong and thermally resilient. The ArmorGlide® coating helps minimize friction and wear, while the strutted design and forced-pin oiling enhance durability and lubrication under hard driving conditions.

Supplied as a complete 8-piston set with floating wrist pins and premium rings, the K398X7 is ideal for full top-end rebuilds. For best results and longevity, make sure to check piston-to-wall clearances, ring gap, and head clearance during installation.