Horse names

Hi,

   I was wondering if any one can help me out. I am buying a horse with the name Clint Eastwood. I would love to change it but have always been told that it is bad luck to change a horses name. I just was wondering if anyone bealived that too and if anyone would have a suggestion as for a nick name for him. See my brothers name is the same so it is weird to be calling my horse and have my brother answer.lol Any suggestions would be great. I was thinking of calling him Mort.

Kim