Not sure I am understanding your post. 0.040" off the head is almost indistinguishable when installed. Your tension / idle pulley will make up for the fact that your cams are now 0.040" closer to the crank shaft.
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)