ARP GM V6 & V8 Hex Bellhousing Bolt Kit

The ARP GM Hex Bellhousing Bolt Kit provides the fasteners needed to secure a compatible transmission bellhousing to the engine block. It is designed primarily for traditional Chevrolet Small Block, Chevrolet Big Block, and select GM six-cylinder and V8 applications using six 3/8"-16 bellhousing bolts.

Each kit includes six hex-head bolts and matching washers. The bolts are manufactured from ARP 8740 chromoly, treated with a black oxide finish, and feature a 1.375-inch under-head length.

Features

• Bellhousing-to-engine-block fastener kit
• Designed for compatible GM and Chevrolet engine applications
• ARP 8740 chromoly construction
• Black oxide finish
• Hex-head design
• 3/8"-16 thread size
• 1.375-inch under-head length
• 7/16-inch hex wrenching size
• Includes six bolts and six matching washers
• ARP part number 129-0901

Fitment

Chevrolet Small Block V8

• 265 cubic-inch Small Block
• 283 cubic-inch Small Block
• 302 cubic-inch Small Block
• 305 cubic-inch Small Block
• 307 cubic-inch Small Block
• 327 cubic-inch Small Block
• 350 cubic-inch Small Block
• 400 cubic-inch Small Block
• Other compatible traditional Chevrolet Small Block applications

Chevrolet Big Block V8

• 396 cubic-inch Big Block
• 402 cubic-inch Big Block
• 409 cubic-inch Big Block
• 427 cubic-inch Big Block
• 454 cubic-inch Big Block
• 496 cubic-inch Big Block
• 502 cubic-inch Big Block
• 572 cubic-inch Big Block
• Other compatible Chevrolet Big Block applications

Additional GM Applications

• Select General Motors four-cylinder engines
• Select General Motors six-cylinder engines
• Select General Motors V8 engines

Engine family or displacement alone does not guarantee compatibility. Confirm that the engine block and bellhousing require six 3/8"-16 bolts with a 1.375-inch under-head length before ordering.

This kit should not automatically be applied to newer GM LS- or LT-series engines, which may use different fastener sizes and application-specific bellhousing bolt kits.

Specifications

• Fastener location: Bellhousing to engine block
• Fastener style: Hex-head bolt
• Thread size: 3/8"-16
• Under-head length: 1.375 inches
• Hex wrenching size: 7/16 inch
• Material: ARP 8740 chromoly
• Finish: Black oxide
• Quantity: 6 bolts

Recommended Use

Recommended when installing a compatible manual or automatic transmission bellhousing on a traditional Chevrolet or GM engine. The kit is suitable for drivetrain repairs, engine swaps, restoration projects, street-performance builds, and racing applications requiring the specified bolt dimensions.

These bolts attach the bellhousing to the engine block. They are not intended to replace the separate transmission-to-bellhousing fasteners, torque-converter bolts, flywheel bolts, flexplate bolts, or clutch pressure plate bolts.

What’s Included

• 6 ARP hex-head bellhousing bolts
• 6 matching washers
• ARP part number 129-0901

The bellhousing, transmission, alignment dowels, inspection cover, starter hardware, and other drivetrain fasteners are not included.

Installation

Inspect and clean the threaded holes in the engine block before installation. Make sure the bellhousing is fully seated over the engine’s alignment dowels before tightening the bolts. The bolts should not be used to pull a misaligned bellhousing against the block.

Start every bolt by hand, then tighten the fasteners gradually using the appropriate sequence. Follow ARP’s general torque recommendations and the engine or bellhousing manufacturer’s requirements for the specified thread lubricant or sealer.

Verify that each bolt provides adequate thread engagement without bottoming in the engine block. Professional installation and a bellhousing-alignment inspection are recommended for performance drivetrain applications.