Former Blog Posts not Found on Google Search

The Skinny: I had a WP.com blog site that was active from Dec up to this week where I have now gone to a hosting site. I transferred/exported the old blog and uploaded it to the new site and had the DNS servers redirected. So all is good except that my past posts are not showing up. If you search a past post in Google it shows up but when you click on the link it comes to a page that says its not found. The site name has not changed. Is there a way to have these posts redirected or refound by the search engines.

Thanks

Bob