Easiest measurement for me to take that clearly shows the difference is using a set of calipers and from the top of the hole in ear to the end of the ear is .240-.250" on the short eared version. The newer NM is .300"+ with that same measurement. Hope that makes sense.
Not sure by the number as I don't have one with the taller ears. Someone on the forum might be able to chime in. I will add measurements at least in the morning.
Wanting to remove the steel XR3 grip frame(Flattop .44 Special) and replace With NXR3 Red aluminum frame but as I found out there are 2 different ear heights on the new models. I have a NM NXR3 Red but it has the shorter ears. Any help finding one would be appreciated. Thank you