In April 2003, Mr. SOS joined the group on the album SouthernUnderground, which was independently released on Freshchest Records. The album featured guests including Masta Ace, Supastition and others, alongside production from Domingo and RJD2, but again mostly Kno. M.F. DiBella of AllMusic commented on "a lyrical deftness and genuine feel for the music rarely seen in the bling-conscious rap of the latter-day era".

The group landed a distribution contract with Caroline Distribution in 2004, and SouthernUnderground was the first project re-released after inking the deal with Will Rap For Food being re-released shortly thereafter in 2005.