4-Bolt Crank Spacer for Holley Mid-Mount Accessory Drive | 70-80 Ford 351W 351C 400M | 97-447 SKU: 809513

Crank Spacer for Holley Mid-Mount Accessory Drive | 70-80 Ford 351W 351C 400M

For use with 3.375" length, 4-Bolt Harmonic Balancer

Dial in proper pulley alignment on your Ford serpentine conversion with this Holley 4-Bolt Crank Spacer, designed for use with the Holley Mid-Mount Accessory Drive System. Typically, 1970-80 Ford 351W, 351C and 400M engines use a 4-bolt, 3.375" damper, and this spacer provides the correct stand-off to position the crank pulley exactly where it needs to be for reliable belt tracking and long-term accessory life.

Machined from aluminum and finished in black, this spacer includes the correct-length crank pulley fasteners, taking the guesswork out of installation and ensuring everything stacks up correctly the first time.

Pro Tip: If you’re not sure whether your engine uses a 3-bolt or 4-bolt damper, check before ordering. Also double-check your harmonic balancer length to ensure it matches the spacified 3.375" length for use with this spacer—using the correct spacer is critical for belt alignment and accessory longevity.

• Required for 4-Bolt Dampers – Designed specifically for Ford engines with 4-bolt, 3.375" crank dampers

• Corrects Pulley Alignment – Ensures proper spacing for Holley Mid-Mount serpentine systems

• Complete Installation Kit – Includes properly sized crank pulley bolts

• Precision Machined Aluminum – Accurate fit with a clean, durable black finish

• Holley Engineered Component – Built to integrate seamlessly with Holley accessory drives

Additional Info

• Part Number: Holley 97-447

• Engine Compatibility: Ford 351W 351C 400M

• Year Range: 1970-1980

• Accessory Drive Compatibility: Holley Mid-Mount Accessory Drive System

Specifications:

• Material: Aluminum

• Finish: Black

• Thickness: 0.575"

• Crank Pulley Bolt Pattern: 4-bolt

• Crank Pulley Diameter: 3.375"

• Fasteners Included: Yes

• Warranty: Manufacturer’s limited 90-day warranty

Holley's 4-bolt crank spacer is a must-have for 1970-80 Ford 351W, 351C & 400M serpentine setups for proper pulley and belt alignment with the Mid-Mount system.