A perforating gun assembly for a monobore application eliminates a full bore isolation valve or other component that has a limiting internal or external dimension and is designed to remain in position after firing. The assembly is run into the hole on a string with a running tool and left in position with the string and the running tool removed. Pressure pulses communicate with a detonation control system to open a poppet to pressurize a chamber with a firing head. It should be noted that other types firing heads can also be utilized to initiate detonation in the system. Detonation clears the gun internals for flow and opens a gun valve that has no reduction in drift dimension as compared to the gun internal path after detonation. Production takes place through and around the gun. The top of the gun can be entered for future intervention work.