This Billet LT4 Supercharger Lid replaces the upper supercharger lid on all GM LT4 Superchargers for a quick and clean install. Nitrous and fuel are injected into each cylinder from inside of the supercharger lid, providing direct port style distribution. Systems come standard as a single stage with jetting for 100 to 300WHP. This lid is made from a solid piece of billet aluminum with 1/8NPT machined directly into the lid, which makes it easy to add a direct port water/methanol later on.

Genuine Nitrous Express. Part number 20939-00.

Ships from US warehouse.

WARNING: California Proposition 65 — this product can expose you to chemicals known to the State of California to cause cancer or reproductive harm.

Note: Not CARB approved — not for sale or use on pollution-controlled vehicles in California.