Yes if it was me i would replace it. Your already going to have alot of the major components off for a timing belt change so it would make sense to. Plus if i has never had one being an 04 with 70k i would, and also because the added load your going to be putting on everything.
2004 Focus SVT Vortech Boosted
2005 Focus ST
2001 BMW M3
1998 GMW 328 Built LS1 Swap
2009 Mazdaspeed 3 (needs more boost)