Tumblr Custom domain PR 7 Backlinks

Dear Friends, Back in the past it was possible to place Custom domain instead of Sub Tumblr domain. Is it no more or is there any possible ways to place Custom domain into Tumblr account to get high PR 7 backlinks to my money site?Thank you so much

A little Google search goes a long way dear friend: http://www.tumblr.com/docs/en/custom_domains

Yeah it's still possible. My main blog has its own domain name instead of the blog name i registed