Here's why and what's involved:
* Tail Light Panel: The 1972 and 1973 Nova tail light panels are distinctly different in shape and mounting points. The 1973 panel is generally considered more rounded. You cannot simply swap them. You'd likely need to extensively modify the 1973 panel to fit the 1972 body, or find a 1972 panel. This will involve welding, cutting, and potentially bodywork.
* Bumper: The bumpers, while seemingly similar, have different mounting points and brackets. Again, a direct swap is impossible. You'll need to adapt the 1973 bumper's mounting brackets to fit the 1972 frame, which might involve significant fabrication. The bumper itself might require some modification for a proper fit.
* Gas Tank: The gas tank's shape, mounting points, and filler neck location can vary slightly between model years. While a 73 tank *might* physically fit in a 72, the filler neck and associated hoses and lines likely won't line up perfectly. You'll need to check for compatibility carefully. It might require modifying the tank straps or even the filler neck to make it work. Additionally, you must ensure the tank's fuel lines and sending unit are compatible with the 1972 fuel system.
In summary: This is a major bodywork and fabrication project requiring welding, cutting, shaping, and significant mechanical skills. Unless you have extensive experience in automotive body repair and fabrication, it's highly recommended to seek the help of a professional body shop. The cost of professional labor might well exceed the value of the parts.
Consider the alternative: sourcing the correct 1972 parts is generally a more feasible and cost-effective approach. Check salvage yards, online parts vendors (eBay, etc.), and Nova-specific parts suppliers.
