Well, McClintock is more fiscally conervative than Schwarzenegger coudl ever wish to be. He was the only Republican who got my vote during the 2006 elections, and was high up on my list during the 2003 recall election, but I eventually settled with Schwarzenegger (who actually know what fiscal restraint meant back then.)
So, okay: McClintock is
(1) fiscally libertarian
(2) socially conservative
Since (1) is a synonym, basically, for "conservative," I think it's safe to say that he's not a libertarian, but a conservative. You know, on everything.