The Stage 3 assembled BR3 package is right for you if you are looking to make big power with a power adder such as Nitrous, Turbo, or a Supercharger! We came out with this package for customers that want maximum valve train control and longevity for high cylinder pressures and temperatures on an LS3 head. NOT ALL VALVES ARE CREATED EQUAL! We use our Proprietary Severe Duty Stainless Intake valves that consist of a thicker margin to prevent early fatiguing as well as tuliping . Then intake valves also come with a hardened tip. These heads are professionally assembled to include vacuum test, Spring pressures verified and install height set, valve stem heights set to equal lengths to assure the same pushrod length and even preload amongst all lifters which is critical in short travel lifters. Heads include Mueller Performance Custom Intake valves, Ferrea Inconel Exhaust valves, and BTR .685 lift springs with Titanium Retainers. Ready to bolt on and make big power!