Plain Plug Gauge for Sleeve ID Go 4.6 to 4.601 Cyl. 0.0001 Len. 80 to 81; with tapping of M2; NOGO 4.617 to 4.618 Cyl. 0.0001 Len. 10 to 11 / Std. Gauging area should have lapped finish. Gauge No. PPG 4600.4618