Set of 8 Hypereutectic Pistons, 4.280-inch Bore

The Keith Black KB400-030 is a set of eight hypereutectic pistons engineered for Mopar B-Series engines. With a 4.280-inch bore and specific ring groove dimensions of 5/64 x 5/64 x 3/16 inches, these pistons are designed to deliver enhanced engine performance. Crafted from a 390 aluminum alloy enriched with high silicon content, these pistons are heat-treated to meet T6 standards, resulting in a component that is approximately 30% stronger than standard aluminum pistons. Their lightweight design contributes to improved throttle response and quicker RPM changes, while their robust construction ensures durability under high compression and high-temperature conditions. Key race-ready features include strategically located upper compression rings, gas-accumulator grooves for optimal combustion control, drilled oil returns for enhanced lubrication, and spiral-lock retainer grooves for secure assembly. These pistons feature a dome volume of +6.00 cc, which is suitable for a variety of engine builds and compression ratio requirements. KB Performance Pistons are produced by UEM, a manufacturer committed to quality, operating under an ISO 9001:2015 certified Quality Management System.