Here, you can see the difference in the height of the RPM's and Victor's valve cover rails. This gives us several advantages. It raises the valve cover away from the rocker assemblies so high-lift cams, combined with thicker and stronger roller rockers, can be used without hitting the valve covers. The raised rail also keeps the oil farther away from the valve cover gasket to reduce any possible valve cover leaks. With Edelbrock's precision CNC machining, perfectly flat rails ensure a positive leak-free seal.