JE PISTONS Piston Kit - 4.320" - M8 391730

High-boost and high-RPM environments demand pistons engineered for extreme durability and consistent ring seal—this JE Piston Kit delivers both through proprietary grain flow forging and precision internal bracing. Whether you're building a competition engine or maximizing your forced-induction setup, these pistons maintain optimized strength-to-weight ratios and minimize operating noise under sustained load. The ceramic crown coating and skirt treatment protect against heat stress and friction wear, ensuring longevity in demanding applications.

• 4.320" bore diameter
• M8 specification
• Proprietary grain flow forging
• Ceramic crown coating
• Internal and external bracing
• 3D undercrown milling
• Optimized strength-to-weight ratio
• Lateral gas ports
• Accumulator groove design
• High-RPM ring seal stability
• High-boost compatible
• Skirt friction coating
• Offset pin design
• Reduced piston rock
• BDC skirt notches
• Kit includes two pistons
• Premium ring pack included
• Wrist pins and wire locks
• Bolt-on installation