ARP 156-5202 Main Cap Side Bolt Kit Ford 4.6L/5.4L Modular Late Cast Iron M9

Vehicle Fitment

• 1999-2004 Ford SVT Lightning (5.4L SOHC 2V Supercharged, Late Cast Iron M9 Block)
• 2002-2003 Ford F-150 Harley-Davidson Edition (5.4L SOHC 2V Supercharged, Late Cast Iron M9 Block)
• 2006-2010 Ford Mustang GT (4.6L SOHC 3V, Late Cast Iron M9 Block)
• 2006-2010 Ford F-150 (4.6L/5.4L SOHC, Late Cast Iron M9 Block)
• Compatible with any performance build using a late Ford Modular 4.6L or 5.4L late cast iron block with M9 main cap side bolt threads

Fitment Notes

• Designed for late cast iron M9 production engine blocks ONLY - side bolts only, not a complete main stud kit
• Does NOT fit early cast iron M8 Romeo blocks (1991-2005 Crown Victoria, Town Car, early Mustang GT/Cobra) - see ARP 156-5201 for M8 cast iron blocks
• Does NOT fit aluminum blocks - see ARP 156-5001 (early M8 aluminum) or ARP 156-5002 (late M9 aluminum)
• Not compatible with windage tray mounting applications
• Verify block casting and main cap side bolt thread size (M9) before ordering - block identification is critical for correct kit selection

Features

• Made from 8740 chromoly steel, heat-treated in-house to 200,000 psi tensile strength - far superior to OEM main cap side bolts
• Precision J-form threads rolled after heat treatment for exceptional fatigue life - significantly stronger than bolts threaded before heat treat
• 12-point head design allows easy socket access in tight main cap locations
• Eliminates main cap walk and fretting - critical in high-boost and high-RPM Modular engine builds
• Protects the block's cast iron thread engagement zones from repeated assembly stress
• Hardened parallel-ground washers included for even load distribution and accurate torque readings

Specifications

• Part Number: 156-5202
• Material: 8740 Chromoly Steel
• Tensile Strength: 200,000 psi
• Thread Size: M9
• Head Style: 12-Point
• Main Bolt Style: 2-Bolt Side Cap
• Finish: Black Oxide
• Block Type: Late Cast Iron (M9 thread pattern)
• Works with Windage Tray: No
• Nuts Included: Yes (12-Point)
• Washers Included: Yes (Hardened Parallel-Ground)
• Quantity: Complete kit (sold as a set)

Included Components

• 1x Complete set of ARP M9 12-Point Main Cap Side Bolts
• 1x Set of 12-Point Nuts
• 1x Set of Hardened Parallel-Ground Washers

Product Description

The ARP 156-5202 is a Pro Series main cap side bolt kit designed for late Ford Modular 4.6L and 5.4L engines built with the late cast iron block using M9 main cap side bolt threads. This block variant is used in the 1999-2004 SVT Lightning, 2002-2003 Harley-Davidson F-150, 2006-2010 Mustang GT (4.6L 3V), and 2006-2010 F-150 trucks. The factory main cap side bolts on these engines are torque-to-yield fasteners - they stretch during installation and must be replaced during any rebuild or performance build.

This ARP kit replaces them with 8740 chromoly bolts rated at 200,000 psi, with J-form threads rolled after heat treatment for exceptional thread fatigue life. Eliminating main cap walk and fretting is especially important in forced-induction builds like the SVT Lightning and Harley-Davidson F-150, where cylinder pressure and main cap loading are substantially higher than stock. This kit covers the side bolts only - always confirm your block casting uses the M9 thread pattern before ordering, as early cast iron M8 blocks require ARP 156-5201.