Oil pump replacement

Does everyone replace their oil pump when rebuilding one of these
motors?  Is there a reason to do it each time?  Long ago, I had someone
tell me to, and never really thought about it until now, but it seems it
was part of the "while you're at it" list of things to do rather than
necessity (I'm rebuilding a 1500, but figure the same rules would apply
to other motors).

Adrian
http://www.midgetweb.com