Stage X 14/12mm Pro Cylinder Head Stud Kit

The Stage X 14/12mm Pro Head Stud Kit is designed for maximum engine performance and reliability in EJ series engines, with features that improve performance and make installation easier.

• Larger stud
• 12 × ARP M12 x 1.25 8740 Chromoly 12-point nuts
• 12 × ARP 12mm 8740 Chromoly washers
• Hex in the stud end for easy installation

Engines modified to 500+ bhp need the most reliable system for clamping the cylinder heads to the block, so the heads do not lift under load at high boost pressure.

Replacing the standard 11mm Subaru head bolts with 14mm precision-manufactured, super high-tensile, aircraft-grade S99 steel studs and nuts offers many advantages when building an engine: a tensile strength much higher than the OE bolts, more stability from the larger diameter and a more uniform clamping force from the stud and nut arrangement.

Supplied with graphite-based assembly lube, so the correct torque figures can be reached accurately.