Bought because another website said you could also use this to install an expansion port (quadrajet) on a square inlet. This happens on a fairly standard engine and we wanted to keep the 4 hole gasket so we wouldn't mix up the air signal. I was able to get it to work, but I had to fiddle around a bit by drilling and enlarging the holes. The end result, it works well, just note that it is designed for a square bore carburetor to widen the inlet. Good fit and finish and fast shipping.