Water pump pulley not wide enough, shreading belt
 

Hi, First post here but have been member to many other forums (VW, MBZ, Dodge Cummins powered trucks, Honda Motorcycle). I have 43 years experience in automotive.
Here is my question. I have a 2003 XJ8 4.0ltr that has 30,000 miles on it. It is a customer of mine. The car is shreading serpentine belts. I looked at the pullies and all look well EXCEPT the water pump pulley. The belt seems wider than the pulley. It rides up on both sides. ALL other pullies have enough width and the belt has a small gap on each side. The tensioner, idler, and ALL pullies are in great shape.
This car is un-molested with. She has taken it to a British car place in San Luis Obispo Ca and the issue still is un resolved.
Is there TWO different pullies that could be available for this car? I have the part number from the pulley 2W93-8509-BB. I was wondering if the pullies were different between the XJ8 and the super charged XJR? I have looked up the serpentine belts for both and they are different. Any help appreciated.