First Impressions of Mile Marker 503 Conversion Kit Ford & GM 203 N.P.
The Mile Marker 503 Conversion Kit Ford & GM 203 N.P. promises to be a game-changer for owners of older full-time 4WD trucks. This kit, manufactured by Mile Marker, allows you to convert your NP203 transfer case to part-time 4WD, theoretically reducing wear and tear and improving fuel economy.
I’ve always been drawn to older trucks, the kind that were built tough but often came with outdated technology. One of the biggest drawbacks of my ’78 Ford F-250 was its full-time 4WD, which constantly chewed through fuel, especially on long highway drives. I was constantly searching for a reliable and cost-effective solution to convert my truck to part-time 4WD.
Upon unboxing the Mile Marker 503 Conversion Kit, I was immediately struck by the heft of the components. The materials seemed robust and well-machined, giving me confidence in the kit’s overall quality. The kit appeared to be a comprehensive solution, including everything needed for the conversion.
I considered other options, like swapping the entire transfer case, but that would have been far more expensive and involved. Another popular choice is the part-time conversion kits from other manufacturers, but Mile Marker has a reputation for durability, and I wanted to ensure a reliable end result. My initial impression was one of cautious optimism – hoping this kit would live up to its promise and provide a long-term solution for my fuel-guzzling 4WD. I was excited to get it installed and see the difference it would make.
Real-World Testing: Putting Mile Marker 503 Conversion Kit Ford & GM 203 N.P. to the Test
First Use Experience
I installed the Mile Marker 503 Conversion Kit in my ’78 Ford F-250 over a weekend. The installation wasn’t exactly a walk in the park (requiring moderate mechanical skill), but the instructions were clear, and with some help from a mechanically inclined friend, we got it done.
My first test was a simple highway drive, something I dreaded before the conversion because of the constant hum and fuel consumption. Immediately, I noticed a difference: the truck felt smoother and quieter in 2WD, and the fuel economy noticeably improved. I then took it off-road, engaging 4WD to navigate some rocky trails, and the system performed flawlessly, providing ample traction.
Extended Use & Reliability
After several months of using the Mile Marker 503 Conversion Kit, I can confidently say it has proven its worth. There has been no noticeable wear and tear on the converted transfer case components.
Regular maintenance involves checking the fluid level in the transfer case, which is easily accessible, and ensuring the hubs are properly greased. The conversion has significantly reduced drivetrain wear during everyday driving. The Mile Marker kit has significantly outperformed my expectations; it’s a robust, reliable solution that has transformed my old truck.
Breaking Down the Features of Mile Marker 503 Conversion Kit Ford & GM 203 N.P.
Specifications
The Mile Marker 503 Conversion Kit Ford & GM 203 N.P. is specifically designed for the New Process 203 (NP203) transfer case found in many older Ford and GM trucks. The kit includes a replacement input shaft, a mode selector, and necessary hardware to convert the full-time 4WD NP203 to a part-time system. The kit also includes 3/4 Ton Hub PN: 423.
The specifications matter because the NP203 transfer case is known for its robust design but also its inefficiency in full-time mode. The conversion allows for selectable 2WD, reducing drivetrain drag and improving fuel economy.
Performance & Functionality
The Mile Marker 503 Conversion Kit performs exceptionally well, providing a reliable and user-friendly part-time 4WD system. The mode selector is easy to operate, allowing for smooth transitions between 2WD, 4WD High, and 4WD Low.
The kit’s main strength lies in its simplicity and effectiveness, but installation can be somewhat challenging for those unfamiliar with transfer case mechanics. Overall, the Mile Marker 503 Conversion Kit has exceeded my expectations.
Design & Ergonomics
The Mile Marker 503 Conversion Kit components are made from high-quality materials and are designed to withstand the rigors of off-road use. While the kit adds some weight to the transfer case assembly, the benefits of part-time 4WD far outweigh this minor drawback.
The conversion does not significantly alter the truck’s original ergonomics. The user-friendly mode selector makes it simple to switch between driving modes.
Durability & Maintenance
Given its robust construction, the Mile Marker 503 Conversion Kit should last for many years with proper maintenance. Regular maintenance involves checking and changing the transfer case fluid and greasing the hubs.
The simplicity of the design makes repairs relatively straightforward, should the need arise. The Mile Marker kit is designed for longevity.
Accessories and Customization Options
The Mile Marker 503 Conversion Kit does not come with any specific accessories beyond what’s necessary for the conversion. However, the converted NP203 transfer case is compatible with various aftermarket upgrades.
These accessories include heavy-duty shift forks and improved seals. Furthermore, the hubs included in the kit can be further upgraded for even greater strength.
Pros and Cons of Mile Marker 503 Conversion Kit Ford & GM 203 N.P.
Pros
- Significant improvement in fuel economy when driving in 2WD.
- Reduces wear and tear on the drivetrain during everyday driving.
- Provides reliable part-time 4WD functionality for off-road use.
- High-quality materials and robust construction ensure longevity.
- Relatively affordable compared to swapping the entire transfer case.
Cons
- Installation can be challenging for those without mechanical experience.
- Requires periodic maintenance, including fluid changes and hub greasing.
Who Should Buy Mile Marker 503 Conversion Kit Ford & GM 203 N.P.?
The Mile Marker 503 Conversion Kit is perfect for owners of older Ford and GM trucks with the NP203 transfer case who want to improve fuel economy and reduce drivetrain wear. This kit is ideal for off-road enthusiasts who want the flexibility of selectable 4WD.
Someone who isn’t comfortable with moderate mechanical work should probably skip this product, opting to have it professionally installed. A must-have accessory is a good set of tools and a reliable floor jack.
Conclusion on Mile Marker 503 Conversion Kit Ford & GM 203 N.P.
The Mile Marker 503 Conversion Kit Ford & GM 203 N.P. is a worthwhile investment for anyone looking to improve the efficiency and longevity of their classic 4×4. The price is justified considering the benefits of reduced fuel consumption and drivetrain wear.
I would highly recommend this kit to anyone in a similar situation to mine. My F-250 is now more enjoyable and economical to drive. If you’re tired of watching your gas gauge plummet, this kit is a game-changer.