A surgical fastener applying apparatus includes anvil (12) and cartridge half-sections (14)and a clamping lever. The cartridge half-section defines an elongated channel member having a distal portion for releasably receiving a single use loading unit (SULU) and a proximal portion for supporting a firing assembly. The firing assembly (20) includes a stationary housing (26) having a plurality of spaced-apart protrusions (27) disposed along a length thereof, a firing lever (50), and a cam bar (46). The protrusions are releasably engagable within spaced-apart apertures (17) defined within the channel member to releasably secure and align the firing assembly within the channel member. The clamping lever is operably associated with the half-sections and is movable from an undamped position to a clamped position to releasably secure an anvil portion of the anvil half-section in close approximation with the SULU. In the clamped position, the firing lever is actuatable to translate the cam bar to eject staples from the SULU.
