Start with the cold engine and put the number one piston in its top dead center. Disconnect the battery and remove the spark plugs and valve covers. Tighten camshaft bearing cap bolts and use a feeler gauge to measure valve clearance of the first cylinder, while noting any out-of-spec measurements. Rotate crankshaft 1/3 revolutions for other cylinders' valves check. To adjust the position camshaft lobe upward, depress the valve lifter, and remove the adjusting shim. Measure the thickness of the shim, calculate the thickness of the replacement shim, and install the new shim. Confirm with a feeler gauge. Repeat for all valves requiring adjustment then replace all removed parts.