Gasket, valve rocker arm cover.
NAA, NAB, 2000, 2031, 2111, 2120, 2131, 4000, 4000SU, 4030, 4031, 4040, 4110TR, 4120, 4121, 4130, 4131, Industrial: 1801, 1811, 1821, 1841, 1871, 1881, 2030, 2130.