Way back in the early 1970's Ford went to the Quadrajet for their 427 Cobra Jet engines because nothing they were using would get them thru emissions.
They should have stayed with them, and over the next ten years or so tried several different carburetors instead.
The 2300 series really aren't all that bad, and Ford exploited them to death and had a few Holley carbs as well for their four barrel applications that didn't do all that bad. They have to be one of the easiest carbs every made to work on.
The variable venturi units were difficult, and all thru the years I've avoided them and most Ford enthusiasts will tell you to do the same thing...