KB PERFORMANCE Piston Kit KB258.030

If you're building or rebuilding an engine that demands precision and longevity, KB Performance pistons deliver the tight tolerances and superior ring seal that separate a reliable build from a mediocre one. The 390 hypereutectic aluminum alloy construction handles extreme temperatures and cylinder pressures while maintaining dimensional stability, and the diamond-machined accuracy means less piston rock and better combustion efficiency across the RPM range. Whether you're a professional engine builder or a serious DIY enthusiast, these pistons reward proper installation with extended service life and predictable performance.

• Material: T-5 heat-treated 390 hypereutectic aluminum
• Weight tolerance: ±1 gram across kit
• Machining precision: ±0.0005 inches piston-to-piston
• Kit includes: Two pistons, pins, spiral-lock clips
• Rings: Hastings moly-coated included
• Installation: Bolt-on replacement, standard clearance required
• Allows tighter bore fit than standard pistons
• Reduced piston rock, improved ring seal
• Optional: Separate ring and clip kits available
• Fitment: Engine-specific—verify application before ordering
• Special attention: Follow included instructions for ring end gap and piston clearance specifications