A Tom has said with the only after market oil pump available for our car the billet gears your still only to 7,700 to 7,800 RPM.
The Oil pump is still the "main" thing, however you start getting valve floating if you don't have upgraded valve springs.
Also their is not much point because even with built motors the Zetec, while it likes high revs, does not do much above 7k. it like the 5k to 6.5k, and takes a fair amount of work to make it make power longer. Either through turbo or some, IMHO, radical NA modifications.
The reason why I was looking for a "better" pump was not to take it over 7,400 RPM but so when I take it to the track and I downshift a little to soon and I peg and or hold it at the 7,400 RPM for a few seconds. Its mostly an insurance option.
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)