Valve Stem Diameter
WARNING: This page is about a different car, the 2013 Nissan Armada. However, it is still accessible from the selected car via links, so may be relevant.
Measure the diameter of the valve stem using suitable tool.
Standard
Intake: 5.965 - 5.980 mm (0.2348 - 0.2354 in)
Exhaust: 5.955 - 5.970 mm (0.2344 - 0.2350 in)
Courtesy of NISSAN NORTH AMERICA, INC.