525 Impeller housing
 

I've researched this and when it's time to change the impeller members are saying to buy the kit not just the impeller, why?

The housing is cheap, and it gets a groove cut in it from the impeller costing you water pressure.

Cp Has A Stainless Kit Pretty Cool

dont forget about the 4oz of drive oil that goes in the seapump for the fuel pump,,

I put the CP stainless one on mine. I don't know why Mercury would use that cheap plastic housing on a "racing" engine! http://www.donzi.net/forums/showpost...6&postcount=38

Hmmm, where exactly does it go, is it marked? This is a for a 2004

What's the best way to get the pulley off the seawater pump and press the new one on? Thanks.

Oil should trickle out this hole with pump installed.
http://i763.photobucket.com/albums/x...es394Large.jpg

This is to r&r the pulley hub. The pulley itself should come right off. If not I'd pry it off with wood.
When you press on the new pulley make sure you support the other end of the shaft and it says to make sure you get it back in the exact position.
http://i763.photobucket.com/albums/x...es392Large.jpg
http://i763.photobucket.com/albums/x...es393Large.jpg