ARP 134-3609 Cylinder Head Bolt Set, ARP2000 Pro Series 12-Point Head

The ARP 134-3609 is a cylinder head bolt kit (head fastener set) from the ARP2000 Pro Series, built with a 12-point head. It is designed for engine builders who want a head fastener with high strength and consistent clamping force.

Key Features:

• ARP2000 Pro Series head bolt kit with 12-point head
• Pro Series bolts are cold-forged, heat-treated before thread rolling and machining, and rated nominally at 200,000 psi
• Application-specific design, typically for competition-only components
• Hardened, parallel-ground washers are included with Pro Series kits to help distribute load evenly and give accurate torque readings
• Reduced wrenching 12-point head and wide-area flange eliminate the need for valve train removal when retorquing the cylinder heads, and allow the use of larger diameter valve springs
• Most Pro Series applications use undercut short bolts, which add stretch to help compensate for head gasket compression and help prevent head gasket failures

Installation Notes: Head gaskets compress on initial torquing, so re-torque the bolts after the engine has been run. Bolts are often the practical choice on street-driven vehicles where the cylinder heads must come off with the engine in the car.