ok so this motor came in a car and i was told it was a 5.0 H.O but not out of a mustang, he said it was out of something else but the same motor. So this is the motor 5.0 with efi, none H.O firing pattern. Has the S stamped on the heads, so I guess they are E6 heads, E9I ecu. Did they make a none H.O. efi motor? Would my ecu work with an H.O. motor or dose the tune have to match the cam.