JE Pistons Ultra Series GM Gen III/IV LS 4.075in Bore/4in Stroke Set of 8 Pistons

JE Pistons is well-known for making some of the strongest pistons available, and their Ultra Series is a prime example. If you're building a serious GM Gen III or Gen IV LS engine, especially one that will see boost or nitrous, these pistons are designed to handle the extreme cylinder pressures. They're built with JE's proprietary Aligned Grain Flow forging technology, which gives them exceptional tensile strength for high-performance applications.

What really sets these Ultra Series pistons apart are the custom-level features you get right out of the box. They come with a thermal barrier crown coating that reflects heat, helping to keep temperatures down and improve how exhaust gases are scavenged. The skirts are coated to reduce friction and noise, particularly noticeable when the engine is cold. Plus, they have lateral gas ports that help maintain a solid seal on the top compression ring, even when you're pushing high RPMs and significant boost. These pistons also feature optimized pin oiling to ensure the pins and bores stay well-lubricated, reducing wear and heat. The included Trend Performance wrist pins are thick-walled and built for the demands of power-adder engines.

This set is configured for a 4.075-inch bore and a 4-inch stroke, with an inverted dome that has a volume of 15.30 cc, suitable for an 8-cylinder engine. It's important to note that these pistons are not CARB approved and cannot be shipped to California. Every component is made 100% in the USA, ensuring you're getting a well-built part for your high-horsepower build.