Blog

Complete head bolt installation walkthrough for 1965–1990 Chevrolet Big Block 396/402/427/454 (12-point) — 25/45/70 torque stages, washer orientation, and the XP984 vs XP980 fitment check.

Complete head bolt installation walkthrough for the 1965–1990 Chevrolet Big Block Mark IV with aftermarket heads — 23/46/70 torque stages, washer orientation, and head fitment check.