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 strong internal engine components, and their Ultra Series pistons are a prime example of that expertise. If you're building a GM Gen III or IV LS engine that's going to see serious boost or nitrous, these pistons are designed to handle the extreme cylinder pressures that come with that kind of power.

What sets these Ultra Series pistons apart is JE's proprietary Aligned Grain Flow forging technology. This process maximizes the material's tensile strength, making them incredibly robust for high-performance engine builds. They also come with custom-level features you'd typically only find on fully bespoke race pistons. You get a thermal barrier crown coating that reflects heat back into the combustion chamber, helping to keep piston crown temperatures down and improve how efficiently exhaust gases are scavenged. The skirts have a special coating to reduce friction and wear against the cylinder walls, which also helps quiet down the engine, especially when it's cold. Plus, lateral gas ports are included to help maintain a solid ring seal, even at high RPMs and under significant boost.

This set includes eight pistons, each with a 4.075-inch bore and designed for a 4-inch stroke. They also come with high-strength, thick-wall wrist pins from Trend Performance, built to withstand the demands of power-adder applications. Every feature on these pistons is optimized for high-horsepower racing engines, and they are made 100% in the USA. Keep in mind these are not CARB approved and cannot be shipped to California.