I think they even made a 1 bbl version. You occasionally see them on ebay. If you choose to use the Clifford 4 bbl, I think you need a few other special parts, like a kickdown system which Edelbrock sold (google). While at it, Edelbrock also sold an aluminum valve cover for the slant which is slick, especially if painted a wild color.
I have a 1bbl economiser on my 64 Valiant. It did help fuel mileage slightly, but limited RPM a lot. As for the clifford intake, be aware that the stock exhaust manifold will not work.