I just finished installing a set of MotoBlue UD pulleys on another 05 Mustang. This time the install went much quicker, the whole job took about an hour, except----
BE CAREFUL...
There is a bolt that comes out of the alternator support bracket on the left side of the car that interfered with the water pump Pulley. I did not notice it at first and it ripped up the belt.
I had to cut the end of the bolt off with a cut off wheel on a dremmel tool. I only took off about 1/16". Finding a replacement belt for an '05 GT was a bit hard. You can't go by the PNs, the autoparts stores won't have anything for a car this new.
I wound up having to take the other belt with me and with the help of an absolutely gorgeous blonde at AutoZone, find one that was the same size.
After replacing the belt, the engine started and there was no more interference. The car ran great. Quite a noticeable increase in performance during acceleration at the lower RPM range.
Here are a set of instructions.
UD Pulley Instructions