ARP BBC Head Stud Kit for Merlin Cylinder Heads

ARP Big Block Chevy (BBC) head stud kits for Merlin cylinder heads are high-strength cylinder head studs (also called head stud kits or head bolt kits). They are built for engine builders who want accurate, consistent clamping force in a performance or competition engine. Each kit is engineered for use with Merlin-style cylinder heads on Mark IV big block applications.

Key Features:

• Premium 8740 chromoly alloy: ARP uses this alloy for its studs and rates it well above standard Grade 8 hardware.
• Heat-treated to 200,000 psi: Studs are heat-treated for full heat penetration and high tensile strength.
• Thread rolled after heat treatment: This improves fatigue strength over studs that are threaded before heat treatment.
• Centerless ground: Each stud is machined to be as concentric and straight as possible. Gaskets and heads seat and align smoothly during installation.
• Complete kit hardware: ARP Pro Series kits are supplied with hardened parallel washers for even load distribution and accurate torque readings.
• Specialty options: Some kits in this line use undercut studs, which balance the stretch between stud lengths for more consistent clamping force as the head gasket compresses.

Studs let you torque the heads without twisting the fastener in the block. That gives more even gasket loading and better sealing than standard head bolts. They are a proven upgrade for high-compression, turbocharged, supercharged, nitrous and other high-load big block builds. ARP fasteners are made in the USA.