I had over 200 articles written for my website. The articles are 100% unique and are working good on getting my site traffic. I'm starting a new website in the same niche and I would like to re-use the same articles. I've done about 50 posts so far with the same articles, my site and blog which is integrated are both a PR4 and some of the articles have already ranked PR 1-2. Is this safe? Will Google penalize my original site if it finds these articles on new site? I slightly change the titles when posting but the content is the same from the original site. I also like to use the articles to build the keywords associated with my site. I know there are sites out there with content that has been duplicated far more then twice. Any suggestions and opinions are appreciated.