JE Pistons Ultra Series GM Gen III/IV LS 4.005in Bore/3.622in Stroke Set of 8 Pistons

JE Pistons' Ultra Series pistons start with a unique Aligned Grain Flow forging process, a proprietary method that maximizes tensile strength. This is crucial for handling the extreme cylinder pressures you'll encounter when building a high-horsepower LS engine, especially one that will see boost or nitrous.

These aren't just strong pistons; they're packed with features you'd typically only find on custom builds. The thermal barrier crown coating reflects heat back into the combustion chamber, helping to keep piston crown temperatures down and improving how efficiently exhaust gases are scavenged. You'll also find a skirt coating that reduces friction and wear on the piston skirts and cylinder walls, which also helps quiet things down, particularly during a cold start. Lateral gas ports are included to help maintain a solid ring seal, even at high RPMs and under significant boost. To top it off, they come with high-strength, thick-wall wrist pins from Trend Performance, designed specifically for the demands of power-adder builds. Every feature is optimized for high-horsepower racing engines, and they're all made 100% in the USA.

This set is designed for a 4.005-inch bore with a 3.622-inch stroke, featuring a flat-top piston with a -5.00cc dish. They use a 0.927-inch pin. Keep in mind these pistons are not CARB approved and cannot be shipped to California. If you're building a serious LS engine that needs to handle serious power, these pistons are a well-built choice.