Plain Plug Gauge for ID in Pre Drilled Arm Go 11.2 to 11.203 Cyl. 0.0001 Len. 50 to 51 with tapping of M4; NOGO 11.248 to 11.25 Cyl. 0.0001 Len. 10 to 11 / Std. Gauging area should have lapped finish. Gauge No. PPG 11200.11250