BBM Flat Top Piston Set 4.350 Bore -5cc

The BBM Flat Top Piston Set 4.350 Bore -5cc from KB Performance Pistons delivers the precision and durability demanded by serious engine builders and high-performance enthusiasts. Engineered for small-block engines requiring a 4.350-inch bore diameter, this piston set represents a proven solution for naturally aspirated and moderately boosted applications where combustion chamber volume control is critical. Whether you're building a street performance engine, preparing for competition, or restoring a classic with modern reliability, KB Performance's flat-top design provides the foundation for efficient power production and consistent ring seal integrity across the RPM band.

The -5cc dome (or in this case, flat-top configuration) decreases combustion chamber volume, raising compression ratio and promoting more complete fuel burn—essential for maximizing torque and throttle response on naturally aspirated builds. KB Performance's manufacturing process ensures tight piston-to-bore clearance tolerances and uniform ring groove dimensions, reducing blowby and extending component life under sustained load. The flat-top design minimizes quench zones and optimizes flame travel within the cylinder, improving combustion efficiency while keeping piston weight manageable for reliable valve-to-piston clearance. Premium-grade aluminum alloy construction with proprietary heat-treating provides thermal stability and resists skuffing in high-load scenarios, while the skirt geometry is optimized for minimal friction without sacrificing lateral stability.

This piston set is ideal for engine builders targeting increased compression ratios on 4.350-bore small-block platforms, including popular Chevy variants and similar displacement packages. Proper installation requires verification of piston-to-deck clearance, rod length compatibility, and complete ring end-gap verification before final assembly—critical steps that directly impact reliability and performance longevity. Pair this set with quality connecting rods, a precisely honed cylinder, and a comprehensive ring package matched to your specific application for optimal results. The 19.25 lb set weight reflects a complete, ready-to-assemble package designed for builders who demand consistency, repeatability, and proven performance from every component in their engine bay.