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There are two kinds of content that Google sees. One is evergreen, the other is fresh. Evergreen might be something that doesn't need to change (not all sites and pages change all the time), with fresh being the likes of articles and news. If there is a thread with good information on it, then it might still be useful. However, if you think there are a handful of forum pages that could be redirected to main internal pages, then you can do this as well - there is no need to redirect every thread though. You could redirect 10 pages and 404 everything else. -Andy