ARP 207-4302 Custom Age 625+ Ultra-Duty Head Stud Kit – 7-Bolt Mitsubishi 4G63 (M11)

Upgrade your engine’s clamping power with the ultimate-tier ARP 207-4302 Head Stud Kit for 7-bolt Mitsubishi 4G63 engines. Manufactured from ARP's proprietary Custom Age 625+ super-alloy, these fasteners are heat-treated to a massive 270,000 psi tensile strength. This kit provides the absolute maximum clamping force available on the market, serving as your ultimate insurance policy against catastrophic head lift on high-horsepower, extreme-boost applications.

Key Features

• Custom Age 625+ Super-Alloy: Premium extreme-grade material rated at a staggering 270,000 psi tensile strength—outperforming standard 8740 and L19 alloys.
• Precision Threads: Threads are rolled after heat treatment to ensure maximum fatigue strength and thread longevity under extreme loads.
• Engineered for 650+ HP: Designed specifically for high-boost turbo setups, E85/race fuel configurations, and maximum-effort competition builds.
• Complete Kit: Includes 10 Custom Age 625+ studs, 10 parallel-ground washers, 10 12-point nuts, and ARP Ultra-Torque assembly lubricant.

Fitment & Application

Features M11 (11mm) thread sizing specifically for late-model 7-bolt 4G63 blocks.

• Fits: 1995–1999 Mitsubishi Eclipse GST/GSX & Eagle Talon TSi (2G DSM)
• Fits: Mitsubishi Lancer Evolution 4, 5, 6, 7, 8, and 9 (Evo IV–IX)

❌ WARNING — WILL NOT FIT:

• Early 1989–1992 6-bolt blocks.
• 1992.5–1994 early 7-bolt blocks (1G DSM), which utilize M12 threads.
• Mitsubishi Lancer Evolution 1, 2, and 3 (Evo I–III), which utilize M12 threads.

Always confirm your exact engine block thread diameter (M11 vs M12) before ordering.

Manufacturer Part Number: 207-4302

Why choose Custom Age 625+ over standard studs?

As cylinder pressures skyrocket from massive boost levels or aggressive fuel configurations, standard fasteners can stretch, leading to head lift and blown multi-layer steel (MLS) head gaskets. Custom Age 625+ delivers nearly a 35% increase in tensile strength over standard 8740 chrome moly. This unmatched material yield strength provides the rigid, extreme clamping pressure required to keep your cylinder head locked down tight to the block under peak combustion pressure.