The pair I had in my hands felt terribly light, and the metal was soft and the texture was not dense. Definitely not Edelbrock quality, but I haven't actually ported a set, and probably will not unless someone locally wanted to try and see what they will flow. When you pick up an Edelbrock, BBM, Pond, etc., you can feel the difference in the metal density and porosity. JMO, but for anything higher performance, I would stay with the known quality for the difference in price. Joe-JDC