Crap - Sorry guys, I had no idea the catalog page was not current
Maybe this thought will be useful - a few years ago I went yarding hoping to replace a 4.56 with atleast a 4.10. The rear fill plug on the HO52 is large enough that if you remove it and use one of those little led flashlights and hold your mouth just right and turn the gears, it IS possible to read the tooth count stamped on the ring gear. That way you can determine the ratio without pulling the cover off of everything.