GM LS Piston Set 4.030 Bore -20.7cc

The GM LS Piston Set 4.030 Bore -20.7cc by RACE TEC PISTONS delivers precision-engineered internal components purpose-built for serious LS engine builders and performance enthusiasts. Whether you're assembling a stroker build, preparing for boost, or optimizing compression ratios in your Gen III/IV LS platform, these pistons form the critical foundation of reliable power delivery. The 4.030-inch bore specification fits modern LS blocks that have been bored to this dimension, making them essential for custom short-block assembly or complete engine rebuild projects requiring exact piston-to-bore clearance.

RACE TEC PISTONS engineered these components with a -20.7cc bowl volume, a negative-displacement design that increases static compression ratio—critical for naturally aspirated builds seeking maximum thermal efficiency and cylinder pressure. This geometry promotes superior flame travel and combustion efficiency while reducing quench distance to minimize detonation risk. The precision-cast construction ensures tight tolerances, consistent weight across the set, and reliable ring sealing under sustained boost or high RPM operation. Each piston in this set is manufactured to exacting standards, with proper pin offset and land design to handle the stress cycles of performance driving or racing duty.

LS engine builders, street rod fabricators, and dedicated track enthusiasts benefit most from this piston set when engineering custom displacement builds or refreshing high-mileage blocks. Compatibility extends across LS1, LS2, LS3, and truck-based LS platforms when the block has been bored to exactly 4.030 inches; verify boring specifications and deck height before ordering to ensure proper compression ratio and piston-to-valve clearance. Installation requires professional machine shop support for proper honing, fitting, and verification of all clearances. The 11.21 lb weight reflects a complete eight-piston set ready for your custom short-block assembly.