02 4.6l oil pump vs 06 4.6l oil pump
 

I have an 02 Seville STS 4.6l I'm rebuilding. I can get a deal on a new oil pump for a 4.6l but its for an 06. The only difference I can see is it takes a different oil pump drive sleeve on the crankshaft. Anyone know why I can't use the 06 oil pump as long as I change the drive sleeve on the crankshaft? Thanks