MACE 12MM HEAD STUD KIT TO SUIT HOLDEN CALAIS VF VT VX VY VZ LS1 LS3 5.7L 6.2L V8Boost engine reliability with our premium 12mm equal length Head Stud Kit, engineered for high performance builds, ensures precise fitment and uniform clamping force. Made from durable 8740 chromoly steel, these studs undergo a rigorous cold forging process and are heat treated for better fatigue strength. Rated at 220,000 psi, they provide superior clamping force, reducing head gasket failure. This Head stud kit suits Holden vehicles fitted with LS1