ARP 135-3607 Cylinder Head Fasteners High Performance 8740 Chrome Moly Hex Head Bolt Kit

The ARP 135-3607 cylinder head fastener kit delivers professional-grade clamping force and reliability for high-performance engine builds. Engineered with premium 8740 chrome moly steel, these fasteners are rated at 180,000 psi—15% stronger than Grade 8 hardware—providing the strength and consistency demanded by competitive racing applications.

Superior Manufacturing Process:

• Precision heat-treated to 180,000 psi using vertical rack positioning for complete, uniform heat penetration
• Centerless ground to exacting tolerances for perfect concentricity and straight, true alignment
• Thread rolled after heat treatment for approximately 1000% better fatigue strength compared to pre-heat-treat threading
• Cold-forged construction ensures complete molecular integrity throughout each fastener

Design Features:

• Reduced wrenching hex head with wide-area flange eliminates valve train removal for cylinder head retorquing
• Allows use of larger diameter valve springs without clearance issues
• Undercut short bolts (where applicable) provide increased stretch to compensate for head gasket compression
• Hardened, parallel-ground washers included for even load distribution and accurate torque readings

Installation Benefits:

• Precision manufacturing allows cylinder heads and gaskets to glide into perfect alignment during assembly
• Consistent clamping force helps prevent blown head gaskets and ensures optimum engine sealing
• Easier, faster engine assembly and servicing—critical for racing applications requiring frequent maintenance

Each fastener is individually inspected and manufactured to ARP's zero-defect, zero-failure quality standard. Look for the ARP stamp on each piece as your assurance of premium quality. This kit represents the preferred choice of professional engine builders across all forms of motorsports competition.

Note: Re-torque all fasteners after initial engine run-in to compensate for head gasket compression and ensure proper clamping force is maintained.