Upgrading a 1982 International 1724 for Modern Utility

[MikePhua]

The International 1724 and Its Historical Role
The International 1724 was part of the S-series medium-duty truck line produced by International Harvester during the late 1970s and early 1980s. These trucks were built for versatility, serving in municipal fleets, construction sites, and agricultural transport. With a GVWR typically ranging from 27,000 to 33,000 lbs, the 1724 was often configured as a flatbed, dump truck, or utility hauler. Powered by gasoline or diesel engines—commonly the MV404, MV446, or DT466—the 1724 featured a rugged frame, leaf spring suspension, and manual transmissions like the Spicer 5-speed or Fuller 10-speed.
Though production of the S-series ended in the mid-1980s, thousands of units remain in service, prized for their mechanical simplicity and rebuildable components. However, upgrading a 1982 model to meet modern performance, safety, and comfort standards requires a strategic approach.
Evaluating the Upgrade Path
Before diving into modifications, it’s essential to assess the truck’s current condition:

• Frame integrity and rust levels
  
• Engine compression and oil pressure
  
• Transmission and clutch wear
  
• Brake system type (hydraulic vs. air)
  
• Electrical system voltage and wiring condition
  
• Cab mounts, steering components, and suspension bushings
  

A full mechanical inspection helps determine whether the truck is a candidate for restoration or if a drivetrain swap is more practical.
Engine and Powertrain Options
Many 1724s came with gasoline engines, which are increasingly impractical due to fuel cost and parts scarcity. Upgrading to a diesel powerplant offers better torque, longevity, and fuel economy. Popular swap candidates include:

• International DT466: A direct-fit option with proven reliability and parts availability. Produces up to 250 hp and 800 lb-ft of torque.
  
• Cummins 6BT (5.9L): Compact, powerful, and widely supported. Requires custom mounts and transmission adapter.
  
• Caterpillar 3116 or 3126: Found in many vocational trucks, though more complex electronically.
  

Transmission upgrades may include:

• Allison automatic: Ideal for urban or utility use, reduces driver fatigue.
  
• Fuller 6-speed manual: For heavy hauling and better gear control.
  

In one case from a contractor in Idaho, a 1724 originally equipped with a MV404 was retrofitted with a DT466 and Allison MT643. The result was a 30% improvement in fuel economy and smoother operation on steep grades.
Brake System Modernization
Many older 1724s use hydraulic brakes, which can be adequate but lack the stopping power and redundancy of air brakes. Upgrading to air brakes involves:

• Installing an air compressor and reservoir tanks
  
• Replacing brake chambers and plumbing
  
• Adding a dual-circuit foot valve and parking brake system
  

This upgrade improves safety, especially when towing or hauling heavy loads. It also allows compatibility with modern trailers and equipment.
Electrical and Lighting Enhancements
The original wiring harness on a 1982 truck is often brittle, corroded, or undersized for modern accessories. Recommended upgrades include:

• Replacing the entire harness with a 12V modern loom
  
• Installing LED headlights, marker lights, and work lights
  
• Adding a fuse panel and relays for accessories
  
• Upgrading the alternator to 120 amps or more
  

Some owners install a secondary battery bank with isolators to power winches, radios, or hydraulic pumps.
Cab Comfort and Ergonomics
The 1724 cab is utilitarian, but upgrades can improve driver experience:

• Installing air suspension seats
  
• Adding sound-deadening insulation to the firewall and floor
  
• Retrofitting HVAC systems with modern compressors and controls
  
• Replacing gauges with digital clusters or multi-function displays
  

In one restoration project in Texas, a 1724 dump truck was fitted with a Bluetooth stereo, backup camera, and air-ride seat sourced from a late-model Freightliner. The driver reported reduced fatigue and better situational awareness.
Suspension and Axle Considerations
The leaf spring suspension can be retained or upgraded depending on use:

• Replace worn bushings and shackles
  
• Add helper springs or air bags for load support
  
• Upgrade shocks to gas-charged units
  

Axle upgrades may include swapping to newer Dana or Rockwell axles with better gear ratios or disc brakes. Ensure compatibility with wheel bolt patterns and driveline angles.
Legal and Registration Implications
Before performing major upgrades:

• Check local regulations for emissions compliance
  
• Ensure VIN and engine numbers match registration
  
• Update GVWR ratings if capacity changes
  
• Verify insurance coverage for modified vehicles
  

Some jurisdictions require inspection or certification after drivetrain swaps or brake system changes.
Conclusion
Upgrading a 1982 International 1724 is a rewarding endeavor that blends vintage durability with modern capability. Whether repowering with a diesel engine, modernizing the brake system, or enhancing cab comfort, each improvement extends the truck’s usefulness and safety. With careful planning and mechanical discipline, the 1724 can continue serving in the field for decades to come—proving that old iron still has a place in today’s demanding work environments.