SEOMike - 9:57 pm on Sep 29, 2011 (gmt 0)

Wouldn't google be unhappy to see a 410 come back to life?

Probably. There are two things in the spec that make me say that; 1. "This condition is expected to be considered permanent." and 2. "This response is cacheable unless indicated otherwise."

404's sound good then.

Eh - maybe, maybe not... I don't really like 404ing a large number of pages because I think it makes your site look broken. If we're talking about a small fraction of pages being 404'd, then it might not be that big of a deal. I don't know where the tipping point for "too many broken pages - reduce ranking" would be.

This might be an opportunity to experiment with a couple server responses and see what works best. Maybe try 404ing some of them, try 302ing some of them to different pages, and maybe 403 some of them to see which response works better for getting the pages re-indexed and re-listed.