VALVE SEAT TOOL KIT 31 PCS HIGH CARBON STEEL CUTTER. VINTAGE BLOCK HEADS HQ. At 45 DEGREE + 90 DEGREE. At 30 DEGREE + 60 DEGREE. SEAT BORE CUTTERS 70°. 8 stem guide in the following sizes. 5/16″, 3/8″, 11/32″, 7/16″. 7MM, 8.5MM, 9MM, 10MM. Not suitable for Modern / Hardened valve seats. NOW IN VINTAGE STYLE METAL CASE. Track Page Views With.