ARP 201-4703 CA625+ Head Stud Kit S63 for BMW M5/M6/X5M/X6M 4.4L V8 Turbo

Vehicle Fitment

• 2012-2016 BMW M5 (F10, 4.4L S63 Twin-Turbo V8)
• 2018-2023 BMW M5 (F90, 4.4L S63 Twin-Turbo V8)
• 2012-2018 BMW M6 (F06/F12/F13, 4.4L S63 Twin-Turbo V8)
• 2010-2013 BMW X5M/X6M (E70/E71, 4.4L S63 Twin-Turbo V8)
• 2015-2018 BMW X5M/X6M (F85/F86, 4.4L S63 Twin-Turbo V8)
• 2018+ BMW X5M/X6M (F95/F96, 4.4L S63 Twin-Turbo V8)

Fitment Notes

• Also listed by one retailer as fitting the 2020+ BMW M8 (F91/F92/F93, S63 V8) - not independently confirmed by a second trusted source, so verify directly before ordering if this is your application
• Undercut design for even clamping and load distribution
• ARP installation paste (assembly lubricant) is required and recommended for proper torque accuracy - confirm it's included or purchase separately

Features

• Prevents head lift and factory bolt stretch/failure on boosted S63 builds pushing well beyond factory power specifications
• Manufactured from Custom Age 625+, a super-alloy with 260,000-280,000 psi tensile strength - substantially higher than ARP2000's 190,000 psi
• Superior fatigue cycle life and toughness, with complete resistance to atmospheric corrosion and oxidation
• Threads rolled after heat-treat for roughly 2000% (20x) better fatigue strength than studs threaded before heat-treat
• 12-point head/nut design for precise, consistent torque application
• Undercut stud design promotes even clamping load across the head
• Includes hardened parallel washers for accurate, repeatable torque readings

Specifications

• Part Number: 201-4703
• Material: Custom Age 625+
• Tensile Strength: 260,000-280,000 psi
• Head/Nut Style: 12-Point
• Stud Type: Undercut
• Engine: BMW S63 (4.4L Twin-Turbo V8)
• Category: Cylinder Head Studs

Included Components

• Custom Age 625+ Head Studs (Full Set)
• 12-Point Nuts
• Hardened Parallel Washers

Product Description

The ARP 201-4703 is a Custom Age 625+ head stud kit purpose-built for the BMW S63 twin-turbo V8, the engine found across the M5, M6, X5M, and X6M lineup spanning multiple chassis generations. As power output climbs beyond factory specification on a boosted S63, the head and block can begin to separate under cylinder pressure, stretching and eventually failing the factory head bolts - this kit exists specifically to prevent that failure mode.

Custom Age 625+ is ARP's premium super-alloy, rated at 260,000-280,000 psi tensile strength versus 190,000 psi for the more common ARP2000 material, with superior fatigue cycle life and complete resistance to atmospheric corrosion and oxidation. Threads are rolled after heat-treating rather than before, which gives roughly 20 times better fatigue strength than conventionally threaded studs, and the undercut design promotes even clamping load distribution across the head for consistent sealing under boost.

This is the studs of choice for S63 owners pushing serious boost levels - whether chasing a high-horsepower street tune or building toward a dedicated race application - where the added margin over even ARP's own ARP2000 line becomes worthwhile. As with any head stud installation, use ARP's assembly lubricant and follow the specified torque sequence and values precisely to get the full benefit of the upgraded material.