I've always wondered if anyone ever compared performance of the aluminum Edelbrock to the '70, '71 Chrysler production cast iron intake manifold straight up? Maybe it was perceived or fact that the Edelbrock 3X2 aluminum intake was a better performer and some owners jumped to the aluminum Edelbrock right away or a little later because of that thought? Could have been a deal closer if the owner worked it right at purchase. Edelbrock had a pretty good performance image going during those days plus being aluminum and lighter and "cooler" as in hip, who knows???