Yeah from what I heard Mercruiser made all of the forum websites take down the links to free online service manuals, so unless you're lucky to find one that wasn't removed, you'll have to purchase the hard copy - Lucky for me I had the manual for a Gen V 7.4 litre and Bravo III outdrive already saved on the computer. Let me know if you need either of those and I can sendem...
I was going to send you to the I boats link but I see they just pulled the service manuals off in July, not sure why. I down loaded mine last year, I have Merc 3.0 with an Alpha II Gen 2 out drive (1996). I can forward the PDF files to you if you want, will need an email. When I did my impeller last fall I used both the Merc and the Sealock manual, between the two it was good, but one by itself did not seem to have all of the information I needed (but that may just be me)