Cylinder head bolt for Perkins 403D-15 to 404D-22 and the related Shibaura N843 / N844 and Caterpillar C1.5 to C2.2 engines (tightening torque 101 Nm). Not suitable for the small blocks 402D-05, 403D-07, 403D-11 and 404D-15. Sold individually, a 4-cylinder requires 14 bolts (11 long of 91 mm and 3 short of 72 mm, measured under the head). Always replace when changing the head gasket.