How do you run an overhead on a C15 cat engine?

To run an overhead on a C15 Cat engine, first ensure the engine is at operating temperature and then remove the valve cover. Rotate the engine to the appropriate position for adjusting the valves, typically aligning the timing marks. Using a feeler gauge, adjust the rocker arms to the specified clearance for both intake and exhaust valves, following the manufacturer’s guidelines. Finally, recheck the adjustments and replace the valve cover securely.