JE Pistons Chevrolet LS Gen III/IV 4.005in Bore 1.300in CH -5.00 CC Piston SetForged in the USA using 4032 aluminum, yielding tensile strength and minimal thermal expansionProprietary Forged Side Relief (FSR) forging design minimizes friction and power loss with reduced skirt width and saves additional weight with a shorter wrist pinLow friction skirt coating reduces wear and reduces operating noise while optimizing performanceIncludes high quality wrist pins, locks, and JE Pro Seal premium piston ringsAccumulator groove helps