I have a old PR 5 site with thousands of sub pages that have PR’s of mostly 5 and 4. I completely revamped the content on my site and my Programmer wants to change the directory structure (out of convenience) eliminating links to the old pages and starting a fresh new directory. My programmer believes that the PR 5 pages will once again be PR5 as Google spiders the content on the new directory. Although I have no evidence I believe that it is better to keep the old well established directory structure as I update the content because I fear that Google will pass off a lower PR to a completely new page. Do my old pages build credibility with Google overtime? Will changing my linking structure affect the PR of my subpages?