Flat Top Piston Set, 4.000" Bore +.030" Oversize

The Keith Black KB134-030 piston set is engineered for demanding applications such as high-performance marine, drag race, circle track, street, or towing builds. Crafted from 390 hypereutectic aluminum alloy, these pistons are heat-treated to T6 standards, resulting in a component that is approximately 30 percent stronger than conventional cast pistons. This enhanced durability allows for tighter piston-to-wall clearances, contributing to improved engine efficiency and longevity. Each piston features a flat top design complemented by two valve reliefs, accommodating various camshaft profiles. The specific dimensions include a 4.000" +.030" oversize bore, a 1.433 in. compression height, and a 5/64, 5/64, 3/16 ring pack. The piston head volume is +7.00cc, and the piston weight is 505g, with the included pin weighing 145g. The pin diameter is .927". These pistons are designed for Small Block Chevrolet 383 stroker engines utilizing a 3.750" stroke and 5.7" connecting rods. The 390 alloy composition provides excellent wear resistance and thermal stability, making them a reliable choice for performance engine reconditioning and upgrades.