I had a site running Wordpress from December 2007 until January 2011. It was a PR4 site with around 2-3000 visitors per day. My host couldn't handle the resources my site used, so they decided to close it down. I decided to go with a standard PHP site so I designed my new home in about two weeks. I still have PR4, but visitors are down to 2-300 per day and I'm pretty much wiped from Google's search listings. When I go into Google Webmaster Tools I have around 2071 Not Found pages so I think that might not be good for my site. Most of it (I would say 80-90%) is non-retrievable from my old site so I can't do a 301 redirect to new pages with similar/same content. What should I do? How can I make Google understand that those links are not to be resurrected, and let it go?