The only thing mentioning float settings I've found is at:
http://www.redlineweber.com/html/Tech/3 ... akdown.htm
Look in the middle bottom of the page. They mention "fuel pressure is critical to float spillage" so if you have not hooked in the fuel return line that could be it. It may be overpowering the needle valve and blasting fuel right by it, overflowing the bowl. The needle valve could also have some grunge in it, dirt or old gas gunk, holding it open. Any way you look at it, a full rebuild kit for the carb might not be a bad idea.