It depends. Did you accept the default target location of /usr/local, or did you modify it? When you enter "which perl", what is returned?

If you did not override the default target location, then yes, there are remnants, particularly in /Library, but they are not harmful as there may be multiple perls in your, uh, oyster. You would then need to control it all with the shebang and your path. I have two versions of perl running just fine on 10.3.

There are documents on Apple's site that detail how to superimpose a new perl over the supplied version. Even if you don't do this, I recommend you find and read them.