Early Model (up to 02/2003 production): M11 bolts

Developed to withstand the extreme conditions of high-horsepower and turbocharged engines

minimizing wear and failure risk

Configurable Maximum Advance

Step 1: Tighten to 25 ft-lbs

B58 Closed Deck Cylinder Head Mod SCR7568 Early Model (up to 02/20035150 AutoSport B58 Closed Deck Cylinder Head Modification Service High horsepower B58 engines are known to experience cylinder head sealing issues due to the coolant jacket design around the combustion chamber. Under extreme cylinder pressure, the factory head flexes and pushes compression into the cooling system, leading to: Cooling system over pressurization Coolant loss Head lift Head gasket failure Unsafe coolant discharge under racing conditions