Update on my Mach 1 vs Cobra question.

Interesting. I knew they have problems with aftermarket pulleys on Mach's, but I never heard anything before about the same problem with '99-'01 Cobra's.

the oil pump on all 4.6 and 5.4s are the same, and all are susceptible to the same issue. (ok, not exactly the same, the DOHC pumps are slightly higher flowing than the standard one....but there is no issue putting a HO pump on a non DOHC car). when the lightweight pulleys are on the motor they dont dampen vibrations as well as the [heavier] stock piece, then the oil pump gears break into pieces.
 
That's an interesting piece of info about the U/D pullies. Mine has Steeda U/D pullies on it, according to their website they are nodular iron. Do the Steeda's have the same problem with the oil pump?
 
Do you guys have a favorite online site that I can use to order factory pulleys?

RockAuto Auto Parts Carries crank dampners for my 99, so they probably have them for your 01. I would think you could get away with just changing out the crank pulley if you can't find the other ones, since I can't imagine a pulley on the water pump and alt having much of an impact on the crank. This means you won't be able to use a standard belt though, you will have to figure one out on your own.