JE Pistons Ultra Series GM Gen III/IV LS 4.135in Bore/3.622in Stroke Set of 8 Pistons

If you're building a high-horsepower GM Gen III or IV LS engine, especially one that will see boost or nitrous, you need pistons that can handle the extreme cylinder pressures. JE Pistons' Ultra Series are designed specifically for these demanding applications. They're not just strong; they're packed with custom-level features right out of the box, all made right here in the USA.

What sets these Ultra Series pistons apart is JE's proprietary Aligned Grain Flow forging technology. This in-house process maximizes the material's tensile strength, giving you a solid foundation for serious power. You'll also find a thermal barrier crown coating, which is a ceramic-based material that reflects heat back into the combustion chamber. This helps keep piston crown temperatures down and can improve how efficiently exhaust gases are scavenged. For reduced friction and wear, the piston skirts are coated, which also helps quiet things down, especially during a cold start. Plus, lateral gas ports are included to help maintain a strong ring seal even at high RPMs and under heavy boost, ensuring consistent power delivery.

This set includes high-strength wrist pins from Trend Performance, designed to handle the rigors of power-adder builds. The pistons themselves have optimized pin oiling features to keep everything well-lubricated, reducing heat and wear. With a 4.135-inch bore and a 3.622-inch stroke, these flat-top pistons are ready for your custom engine build. Keep in mind these are not CARB approved and cannot be shipped to California.