Cm2350

[JimT]

So, I know this is an old thread, but I randomly came across it today. Based on size and type in your initial picture I'd say it looks just like one of those "accessory" mounting bolts cummins uses all over the head on these engines. Fuel rail mounting/support bracket, EGR mounting/support bracket, even the 2.5" upper coolant pipe going across the front of my engine from the thermostat to the top of the radiator has a bracket with a bolt just like that just inches forward of the valve cover. On my cm2250 they are almost all 15mm or 17mm bolts. The smaller 10-12mm ones have shoulders but those bigger ones don't. Unpainted like that suggests a factory screw up, but probably can't prove it.