A system for mounting adjustable shelves (206) in mobile truck body-applications. The system includes integrated attachment means adapted to receive a cross-member (202) for affixing thereto. The integrated attachment means are integrated into the panels forming the compartments (102,112,114,116) of the body side pack. The system further includes one or more shelves (206), which include at least two slots, disposed along the periphery surface of the shelf (206) so as to receive a corresponding fastener (208). The cross-member (202) includes at least two slots, corresponding to the slots in the shelf (206), such that a fastener (208) extends through the slots to secure the shelf to the panel of the compartment.