To change to manual hubs, you'd need to:
* Source manual locking hubs: Find a set of manual locking hubs that are compatible with your specific Power Wagon's axle type (Dana 44, Dana 60, etc. You'll need to identify your axle type first). This is not a straightforward task as finding used parts in good condition for older vehicles can be challenging.
* Potential Axle Shaft Differences: There might be differences in the axle shafts themselves between vehicles originally equipped with automatic vs. manual hubs. This means you might need more than just the hubs – you might need new axle shafts or at least modify the existing ones to fit.
* Complete Hub Assembly: It's likely you'll need more than just the outer hubs. The inner components, including the locking mechanism, might also need replacement or modification.
* Professional Installation: This is not a beginner's job. It requires specialized tools and knowledge of axle disassembly and reassembly. Improper installation could lead to serious drivetrain damage or even injury. A professional mechanic experienced with older 4x4s would be highly recommended.
In short, while theoretically possible, converting from automatic to manual locking hubs on a 1977 Dodge Power Wagon is a complex and potentially expensive undertaking requiring specialized parts and expertise. It's often easier and more cost-effective to simply stick with the automatic hubs unless there's a significant, compelling reason to change.