JE Pistons Ultra Series GM Gen III/IV LS 4.13in Bore/3.622in Stroke Set of 8 Pistons

JE Pistons is well-known for making strong, reliable internal engine components, and their Ultra Series pistons are a prime example of that commitment. If you're building a high-horsepower GM Gen III or IV LS engine, especially one that will see boost or nitrous, these pistons are designed to handle the extreme cylinder pressures you'll encounter. They feature JE's proprietary Aligned Grain Flow forging technology, which is developed in-house to maximize tensile strength, giving you a solid foundation for your performance build.

What really sets these Ultra Series pistons apart are the custom-level features you get right out of the box. The thermal barrier crown coating helps reflect heat back into the combustion chamber, which can improve scavenging and reduce piston crown temperatures. You also get a skirt coating to reduce friction and wear on the cylinder walls, making for a quieter engine, especially when cold. Plus, lateral gas ports are included to help maintain a strong ring seal even at high RPMs and under heavy boost. These pistons are built with high-strength wrist pins from Trend Performance, and every feature is optimized for demanding, high-horsepower racing engines.

This set includes eight pistons, each with a 4.130-inch bore and a flat top design with a -5.00cc dish. They are made from 2618 aluminum and come with a 0.927-inch pin. It's important to note that these pistons are not CARB approved and cannot be shipped to California. All JE Pistons products, including this Ultra Series set, are proudly made 100% in the USA.