Plain Plug Gauge for Sleeve ID Go 4 to 4.001 Cyl. 0.0001 Len. 80 to 81; with tapping of M2; NOGO 4.017 to 4.018 Cyl. 0.0001 Len. 10 to 11 / Std. Gauging area should have lapped finish. Gauge No. PPG 4000/4018