to gain PR wise when exchanging links between your own sites. I have couple domains on different c-class ip but all my domains are registered under my name. Would google count this against me at all?
I am sure at some point they do store that data. You can always change the WHIOS info on the domains to make them unique if you are worried.
I presume you don't mean to change the name? The entity which the domain is registered to needs to be correct otherwise you are risking that your domain can be revoked by ICANN.