ARP Flexplate Bolt Kit for Gen II/LS Small Block Chevrolet — Pro Series M11 x1.5 Aerospace Alloy

These bolts replace factory hardware with a heavier-duty solution designed to resist fatigue and maintain clamping integrity under high-stress conditions. Forged from aerospace alloy and carefully heat-treated before thread rolling and machining, this ARP kit features a flat 12-point head and an increased shank diameter to improve register and shear resistance compared with stock bolts. The kit uses M11 x 1.5 thread size and accepts 3/4 inch wrenching for common garage tools.

How do these bolts improve reliability on high‑torque engines?

ARP bolts are made from a superior alloy and receive a controlled heat treatment that increases tensile strength and fatigue life. The larger-diameter shank reduces the risk of shear failure at the hub while the precise thread rolling produces consistent preload when torqued.

• Forged aerospace alloy construction for higher tensile strength
• Heat-treated prior to thread rolling to improve fatigue resistance
• Larger-than-stock shank diameter lowers shear stress at bolt seat
• Thread geometry yields consistent, repeatable clamp load

What sizing and fitment details should I check before ordering?

This ARP kit is specified for Gen II/LS series small block Chevrolet applications and uses an M11 x 1.5 thread size with a 3/4 inch wrenching head. Verify your flexplate and crank flange accept M11 bolts and confirm the thread pitch matches factory fasteners to ensure proper engagement.

• Part number: 244-2901 — ARP Pro Series flexplate bolts
• Thread size: M11 x 1.5 — match to engine crank or flexplate threads
• Head style: flat 12-point for stronger tool engagement
• Wrenching size: 3/4 inch — compatible with standard hand tools

How are these bolts installed and torqued for best results?

Install bolts into clean, dry threads and follow the vehicle manufacturer’s torque sequence when seating the flexplate. Use a calibrated torque wrench and, if ARP recommends it, specific lube or thread treatment to achieve correct preload without over-torquing.

• Clean crank and flexplate threads before installation
• Use the correct torque sequence and specified torque values
• Apply ARP-recommended lubricant or assembly compound if specified
• Recheck torque after initial run-in per service guidelines

What makes the ARP Pro Series head design beneficial?

The exclusive flat 12-point head increases the contact area for sockets and reduces rounded-corner failures common with smaller bolt heads. That design simplifies installation in tight spaces and helps maintain tool grip during high-torque tightening.

• Flat 12-point profile for improved socket engagement
• Lower risk of tool slippage in confined engine bays
• Durable head geometry that resists rounding under load
• Smoother torque application for consistent clamp force

Who is this for? ARP 244-2901 is intended for engine builders, performance tuners, and Chevy owners upgrading Gen II/LS small block drivetrains who want a durable, serviceable upgrade over OEM flexplate bolts. If you routinely push engines with increased torque, race use, or frequent assembly/disassembly, these bolts offer stronger registration and more consistent preload than stock hardware.