Gen FS

This is the truck

I've got a 2009 CXU 613 here with a MP8 that appears to have been spec'd without an engine brake. Very strange given the larger motor and 13spd transmission, but it's a government truck and you see some weird with them. I'm wondering if the actuators and wiring are under the valve cover? Anybody have any experience with this? I called my local dealer (TEC) the kid I talked to didn't seem to understand anything about the system. Thanks