How's the blower pulley held on?
 

I ordered an upper pulley and was surprised to see that the bore looks straight. I thought it would be tapered, keyed or something. How is it held on? I know it takes a special puller to remove it, but I have not purchased one yet.

Any pointers?

It's pressed on. You will need to either borrow or buy a pulley tool. Most of the major vendors on here carry one.

Otherwise, you can remove the snout and have a shop use a press to remove and install the pulley. This is a bit more of a pain because you have to drain the oil and refill with new.