Forging creates a subtle knitting of the grain and produces directional flow where you need it most. If performance and reliability are needed, a one-piece valve that has been forged by Victory is the way to go. The way Victory valves are produced allows the grain to flow in the opposite direction of the stress of the valve, creating a more resilient part. Two-piece valve assemblies are not free or porosity and are welded together where the stem and head meet - this process is cost effective and cheap to produce. Why cut corners? Did you know other manufacturers valves are welded? Have you ever dropped a valve? Sales people will say a two-piece valve has better properties because of the heat treatment of two different materials... a stiffer stem and a softer head. When it comes down to data, the weld is NOT the problem. The problem is the area above and below the weld. Crystallized grain structure between alpha and beta grains are the problem. Victory valves superior heat treatment is KEY in valvetrain longevity.