LS1 Domed Piston Set 3.903 Bore +4cc

The Wiseco-PRO TRU LS1 Domed Piston Set 3.903 Bore +4cc is a forged performance piston kit engineered for LS-series engine builds demanding high compression and reliable durability. These domed pistons are designed to increase combustion chamber efficiency, making them a core component for builders targeting increased horsepower and torque in street and performance applications. The +4.00 cubic centimeter dome volume is precisely calculated to work within LS architecture tolerances while maximizing compression ratio for naturally aspirated or forced-induction builds.

This Pro Tru Street Series kit features a 3.903-inch bore diameter matching stock or bored LS blocks, with 1/16-inch top and second ring grooves plus a 3.0mm oil control ring groove. Forged construction provides the strength necessary to handle increased boost or cylinder pressure without deformation or failure. The piston dome geometry is optimized for chamber shape compatibility, critical when assembling LS builds where compression ratio directly impacts power output and engine efficiency. Ring groove sizing follows OEM LS specifications, ensuring proper ring seal and minimizing blow-by during combustion.

Builders preparing LS1, LS2, LS3, or LS6 engine builds—whether naturally aspirated street builds, turbocharged applications, or supercharged platforms—rely on precision piston geometry to achieve target compression ratios. The +4cc dome volume is common for 10.5:1 to 11:1 compression ratio builds in LS applications. Complete piston sets enable simultaneous cylinder-to-cylinder consistency, eliminating compression variance and hot spots. This kit is essential for machine shops, performance builders, and enthusiasts executing LS engine assembly where component matching and precise specifications are non-negotiable for engine reliability and peak performance.