Tri-Y DLM LS1 Long Primary 1-3/4 - 1-7/8

The Tri-Y DLM LS1 Long Primary 1-3/4 - 1-7/8 exhaust header is engineered for LS1-powered vehicles and street/strip builds seeking maximum scavenging efficiency and power gains across the RPM band. This tri-Y configuration routes primary tubes from three cylinders into a common collector before splitting into separate secondaries, optimizing exhaust gas velocity and reducing backpressure. Built for enthusiasts who demand serious bolt-on performance without sacrificing reliability, this header bridges the gap between stock efficiency and race-grade aggression.

The long primary design extends tube length to maximize low-to-mid-range torque, a critical advantage for street cars and bracket racers requiring consistent power delivery off the line. Measuring 1-3/4 inch primary tubes that transition to 1-7/8 inch secondary collectors, this stepped approach matches the natural expansion of exhaust gases as they accelerate toward the catalyst converter or downpipe. The DLM (Durable Long-Tube Material) construction provides robust thermal resistance and longevity under sustained high-heat cycles, while the tri-Y layout eliminates cross-over interference that plagues some single-plane designs, allowing each cylinder bank to evacuate independently and efficiently.

This header is ideal for LS1 swap builds, Corvettes, Camaros, and trucks where port velocity and peak horsepower matter as much as streetability. Installation is straightforward on stock or modified LS1 engines; ensure adequate underbody clearance and verify O2 sensor boss compatibility before final fitment. The 34.9 lb weight and compact 20.5 x 9.75 inch footprint keep rotational mass low while fitting tight engine bays. Pair with a quality cat-back exhaust system for optimal results—this header alone typically unlocks 15–25 hp gains depending on tune and supporting modifications.