There is no longer any parole in federal cases, and time off for good behavior is limited to a maximum of 15% of the sentence. So, with credit for the time he already served, he'll do a minimum of 24 years or so.
Persons sentenced to prison in the federal system must serve a minimum of 85% of their
sentence prior to release since the adoption of the Federal Sentencing Guidelines system in 1987.
http://www.sentencingproject.org/doc/publications/inc_truthinsentencing.pdf