I got a site that was ranked #8. It stayed there for a week, and then dropped out of the top 1000. Around 3 months later, it came back for a week, it then dropped again and hasn't been seen since. I have tried building links like nothing happened but the site refuses to return. What do you do with these sites? Should I clone the site on a different domain? And 301 the old site to this? Or will the penalty carry over? Should I forget about the site and build a new site with new content with the same keyword? Thanks!