Complete conversion kit engineered for 1973 to 1980 Ford, Dodge, and GM 3/4 ton vehicles equipped with NP203 transfer cases converting full-time four wheel drive to part-time operation. Includes Mile Marker 423 manual locking hubs.

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Mile Marker NP203 4x2 Conversion Kit with 423 Premium Hubs delivers a complete heavy-duty solution for converting factory full-time New Process 203 transfer cases into efficient part-time four wheel drive systems. Designed for 1973 to 1980 Ford, Dodge, and GM 3/4 ton trucks equipped with the NP203 transfer case and Dana 44HD front axles, this kit eliminates constant front axle engagement while preserving drivetrain strength and reliability. Factory NP203 systems were engineered for full-time operation, keeping the front drivetrain engaged at all times, increasing wear and reducing fuel efficiency. This conversion kit replaces the internal differential components, allowing the transfer case to function in true part-time mode when paired with manual locking hubs. Included Mile Marker 423 Premium manual locking hubs provide durable engagement and dependable axle control built for heavier 3/4 ton applications. By disengaging the front drivetrain during normal driving, this system reduces unnecessary component wear, lowers parasitic drag, and can improve fuel economy while maintaining full off-road capability when engaged. Engineered with precision-machined components and backed by decades of drivetrain expertise, this kit offers professional installers and restoration builders a proven modernization solution for classic heavy-duty trucks. Built for strength, durability, and long-term performance, Mile Marker restores control and efficiency to your drivetrain without compromising capability.

• Complete NP203 conversion system including 423 heavy-duty hubs.
• Converts full-time four wheel drive to true part-time operation.
• Reduces drivetrain wear and parasitic drag.
• Designed for 3/4 ton Dana 44HD applications.
• Includes durable Mile Marker 423 Premium hubs.

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Information:

Engineered specifically for NP203 transfer case applications in 3/4 ton trucks equipped with Dana 44HD front axles. Professional installation recommended. Follow factory service manual procedures during transfer case disassembly and hub installation to ensure proper bearing preload and reliable long-term performance.

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Application Summary:

Year	Make/Model
1975-1977	Chevrolet K20
1973-1974	Chevrolet K20 Pickup
1975-1980	Dodge W200
1973-1974	Dodge W200 Pickup
1973-1977	Ford F-250