Wiseco K398X1 Forged Pistons 4.010" Bore -3.2 cc for GM LS V8

Vehicle Fitment

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

Features

• Forged from high-strength 2618 aluminum alloy for durability
• ArmorGlide® skirt coating to reduce friction and limit wear
• Flat-top crown with -3.2 cc volume for balanced compression
• Anti-detonation and pressure-seal grooves to improve ring sealing
• Floating 0.927" wrist pin for reliable high-RPM performance
• Designed for use with 6.125" rod length (standard LS stroke)
• Includes professional-series ring set (1.2 mm / 1.2 mm / 3.0 mm)
• Suitable for naturally aspirated, nitrous, or moderately boosted applications

Specifications

• Bore Diameter: 4.010 in
• Stroke: 3.622 in
• Compression Height: 1.304 in
• Piston Volume: -3.2 cc (flat-top)
• Piston Material: 2618 forged aluminum
• Wrist Pin Diameter: 0.927 in
• Rod Length Compatibility: 6.125 in
• Ring Groove Sizes: 1.2 / 1.2 / 3.0 mm

Included Components

• 8 x Forged pistons (K398X1)
• 8 x Floating wrist pins (0.927")
• 16 x Retaining clips / Spirolox
• 8 x Ring sets (1.2 / 1.2 / 3.0 mm)

Product Description

The Wiseco K398X1 is part of Wiseco's Professional-series forged piston kits designed for GM LS V8 engines. With a 4.010" bore and -3.2 cc flat-top design, these pistons deliver a reliable compression ratio that supports both naturally aspirated and forced-induction builds.

Built from 2618 alloy, they offer superb strength and fatigue resistance. The ArmorGlide® skirts help reduce friction, while the flat-top crown and precision ring lands contribute to consistent power delivery. Anti-detonation and pressure-seal grooves ensure effective sealing under high load.

This is a full 8-piston set, including matching floating pins and ring sets. Ideal for performance builders doing a complete top-end rebuild on LS engines, it's essential to verify piston-to-wall clearance, ring gap, and dome-to-head clearance during installation for optimal performance and longevity.