Just a follow up to this thread. In 2007 Ford began using the FS20 compressor for the AC.
The pulley listed Motorcraft YB542 will not work on the new style compressor. It will only work on the FS10 model which was used in the F150 up through 2006 as well super duty trucks.

So if you have a 2007 or newer truck and want to go 8 rib you will need the following:
Pulley Motorcraft YB3140
Clutch Coil Motorcraft YB3142
The clutch hub is YB3111. You would only need to purchase this if yours is worn as the part is the same for the 8 or 6 rib set up.

 

Old thread but wanted to let everyone know. You will need the follow water pump pulley: F6TZ-8509-AA, at least on a 2007 F-150 w/ Whipple. The factory pulley does not have enough depth and the belt will rip on the inner lip of the stock F-150 pulley.