Plain Plug Gauge for Awl ID. Go length 25 to 26 (Go Size 4.003 to 4.005 Cyl. 0.001 LEN. 25 to 26 & NOGO 4.095 to 4.1 Cyl. 0.002 Len. 10 to 11 / Std. Gauging area should have lapped finish Gauge No. PPG 4000.4100