Holley Mid-Mount Accessory Drive System | Natural | SBF 289 302 351W | 20-370 SKU: 809500

Holley Mid-Mount Accessory Drive System | Small Block Ford | Natural Finish

If you’re planning a serpentine belt conversion on an Early Bronco or classic Small Block Ford, the Holley Mid-Mount Accessory Drive System is one of the cleanest, most complete solutions available. Designed to pull all accessories tight to the engine, this system eliminates bulky brackets and cluttered layouts in favor of a compact, integrated setup that looks right at home in a classic engine bay—while delivering modern reliability and performance.

By using a custom timing cover and a true bracketless design, this mid-mount system is ideal for Early Broncos where space is limited and engine bay cleanliness matters. It’s equally at home in resto-mod builds, engine swaps, or clean daily drivers where you want modern serpentine reliability without an aftermarket jungle of brackets.

Pro Tip: This system is a great match for EFI swaps and modern cooling upgrades, especially in Early Broncos where space, belt alignment, and reliability are critical.

• Bracketless Mid-Mount Design – Accessories bolt directly to a custom timing cover for a clean, compact serpentine conversion

• Perfect for Early Bronco Serpentine Swaps – Pulls accessories in tight for improved clearance and a cleaner engine bay

• Complete Accessory System – Includes alternator, water pump, A/C compressor, power steering pump, pulleys, belt, adapters, and wiring

• OE-Inspired Engineering – Uses proven C7 Corvette–style components for durability and efficiency

• Natural Finish – Raw, industrial look that fits right into classic and performance builds

What’s Included

• 150-Amp Alternator – C7 Corvette–style with advanced 6-phase technology

• Cartridge-Style Water Pump – Efficient LT1-inspired design

• SD7 A/C Compressor – Compact and reliable

• Type II Power Steering Pump – Includes baffled reservoir for consistent pressure

• Custom Timing Cover – Eliminates traditional brackets

• Serpentine Pulley System & Belt – OE-correct ratios for longevity

• Alternator Harness & Hardware – Everything needed for installation

Compatibility & Configuration Notes

• Engine Fitment: Small Block Ford

• Ideal Use:

  • Early Bronco serpentine belt conversions

  • Classic Ford engine swaps and resto-mods

• Cooling & Hose Options:

  • Dual heater hose return ports (upper center or passenger-side low)

  • Water pump inlet supports driver- or passenger-side lower radiator hoses

• Fuel Pump Compatibility:

  • Works with mechanical fuel pumps (timing cover modification required)

• Crankshaft Compatibility:

  • Supports 3- or 4-bolt dampers (spacers sold separately)

  • Holley #97-448 - For 3.00" Damper (63-69 Ford 289/302/351W with 3-bolt pulley)
    
    
  • Holley #97-447 - For 3.375" Damper (70-80 Ford 351W/351C/400M with 4-bolt pulley)
    
    
  • Holley #97-446 - For 3.875" Damper (91-01 Ford 351W HO or 81-01 Ford 302/351W with 4-bolt pulley)

• A/C Hose Kits Available Separately:

  • Driver-side exit: p/n 809510 (Holley #97-443)

  • Passenger-side exit: p/n 809511 (Holley #97-444)

Additional Details

• Pulley Covers Included – Billet covers for alternator, tensioner, and compressor

• OE Pulley Ratios – Designed for proper accessory speed and long service life

• Installation Support – Full-color, step-by-step instructions included

The Holley Mid-Mount system is a top-tier choice for Early Bronco serpentine belt conversions, for a clean, compact modern front drive system that fits tight.