If you think your contact info will directly & significantly boost rankings move your contact info into an image. Google won't be able to read the contact info if its within an image but your users are still served. That way you can test it and see if its real or tin foil.
Personally I think contact info can be helpful by indirectly influencing other signals but I doubt there is a significant & direct boost due to displaying contact info.
ps Adding local address to a web page can help for local search terms but I think this conversation is more about generic keywords on a national level.