In order to make the AFR work or better yet to use it properly, you must have a very good understanding of how the carb works. You need to know how the idle circuit, transition power and cruise circuits affect the AFR.
Best bet is to get the Holley book with the cut away view of a 4500 on the cover. I don't have mine handy but just check Amazon.
Above all don't get "drill happy" before you understand what you are doing.
The AFR gage simply tells you what is going on. It can be misleading if you don't understand the carb. It's not hard learning you just have to put your mind to it.