Your timing belt will likely have more flex and adjust in length due to tension and thermal expansion. You should be setting you timing TDC so should still not mater...
2001 ZX3 2.0L Zetec-
Hatch Nation #42
Going through Rebuild See "The TICK Build Thread" for details (http://www.focusfanatics.com/forum/showthread.php?t=289168&referrerid=62897)