Wiseco K0421X3905 Chevrolet LS 3.900 Stroker Forged Piston Set 3.905 in. Bore

The Wiseco K0421X3905 is a Professional Series forged piston set engineered for Chevrolet LS 3.900-inch stroker builds.

These LS stroker pistons are geometrically optimized for the 3.900-inch stroke rod angle, resulting in smoother, more precise operation that reduces bore distortion, minimizes crank and rod stress, and maintains a more consistent ring seal throughout the power stroke. The increased compression height design further reduces piston rock and improves cylinder stability for reliable, repeatable performance.

Key Features:

• Forged in-house from 2618 high tensile strength aluminum alloy for superior durability under boost, nitrous, and naturally aspirated high-output conditions
• ArmorGlide® skirt coating provides seizure resistance, reduced friction, and quieter operation
• Includes H13 wrist pins and a 1.2mm / 1.2mm / 3.0mm GFX ring pack for a complete, race-ready assembly
• Fully machined crown with precision ring grooves for optimal ring seal
• Compatible with LS1, LS2, LS3, LS6, and LS9 valve pocket configurations
• Engineered, forged, and machined in the USA at Wiseco's Mentor, Ohio facility

Specifications:

• Bore: 3.905 in.
• Compression Height: 1.165 in.
• Pin Diameter: 0.927 in.
• Stroke: 3.900 in.
• Ring Pack: 1.2mm / 1.2mm / 3.0mm GFX
• Material: 2618 Aluminum Alloy

Wiseco's Professional Series represents a no-compromise approach to piston design — suited for heavy to severe duty race builds where consistency, strength, and precision are non-negotiable. Built for racers, by racers.