how to tell if 10/24 spline front shafts??

Im looking to get a new NSF CV joint for my disco but have been asked if its 10/24 spline. I dont really want to go strip it all down as i need to keep it mobile at the moment and its a next day on the joint. Is there a way to tell what one it is other than stripping it down?

cheers

Jon

if its 300 tid it will be stc3051 which is also tdj000010 which fits 24 pline diff ,