ARP 151-4204 Cylinder Head Stud Kit Chrome Moly - 8740 12-Point

The ARP 151-4204 is a high-performance cylinder head stud kit engineered for serious competition and high-output engine builds. Manufactured from premium-grade 8740 chrome moly steel, these studs deliver exceptional strength and durability that exceeds aircraft-quality standards.

Superior Manufacturing Process:

• Precision heat-treated to 200,000 psi using vertical rack method for complete heat penetration
• Centerless ground after heat-treat for exceptional concentricity and straightness
• Thread rolled after heat-treat for 10x better fatigue strength compared to pre-heat-treat threading
• 12-point head design for precise torque application
• Specially undercut shorter studs equalize stretch for consistent clamping force

Key Benefits:

• Allows cylinder heads and gaskets to glide into perfect alignment during assembly
• Provides more accurate and consistent torque loading than bolts
• Reduces risk of head gasket failure through optimized clamping force
• Stretches only on vertical axis when torquing, eliminating torsional stress
• Ideal for racing powerplants requiring frequent disassembly and service

Each kit includes hardened, parallel-ground washers to ensure even load distribution and accurate torque readings. ARP stamps each stud as assurance of quality and adherence to their zero-defect manufacturing standard. Note that studs should be installed finger-tight in a relaxed mode, and re-torqued after initial engine break-in to compensate for head gasket compression.