Here's why:
* Extensive Wiring: The cab houses a significant amount of wiring for lights, gauges, power accessories, etc. Disconnecting, labeling, and reconnecting all this wiring is incredibly time-consuming and complex. Getting it wrong can lead to electrical problems and potential damage.
* Plumbing: Brake lines, fuel lines, and potentially HVAC lines run through the cab. These need to be carefully disconnected and reconnected, with proper bleeding of the brake system. Leaks are a major risk.
* Body Mounts: The cab is bolted to the frame at numerous points. These bolts can be incredibly stubborn after 30+ years, requiring significant effort and specialized tools to remove and reinstall. Rust is also a major factor.
* Steering Column and Linkage: The steering column and related linkages must be disconnected and reconnected precisely. Misalignment can impact steering and handling.
* Shift Linkage (Manual Transmission): If it's a manual transmission, the shift linkage needs careful disconnection and reconnection.
* Precision Alignment: Getting the cab perfectly aligned on the frame is crucial for proper door alignment, hood alignment, and overall functionality. Improper alignment can lead to stress on the body and frame.
* Specialized Tools: You'll likely need a variety of specialized tools, including a strong impact wrench, torque wrench, and possibly a frame-straightening jig for alignment.
In short: Unless you're a very experienced mechanic with access to a well-equipped workshop and extensive knowledge of 1980s GM trucks, this job is best left to professionals. The potential for costly mistakes and damage is very high. The time involved could easily exceed several days, even for an expert. The cost of professional labor would likely be substantial.
