They come out as a new item about a year ago. Most of the Bronco parts houses used to carry them.
Item #10795 - New OUT OF STOCK
1966-77 Ford Bronco
Made in Black Only
This is a molded plastic box with watertight cover.
Fits in driver’s Side Fresh Air Intake
The boxes are easily installed with common hand tools in the Bronco engine compartment. Many owners can re-use the fresh air box mounting screws to attach their new cowl boxes.
NOTE: Production units are BLACK As all Bronco owners know, space is at a premium in the small trucks, and the cowl box provides another location to store extra fluids, tools, or other items that the owner chooses. If the hood has a locking mechanism, the box also becomes a secure storage location for valuables. The production models are black in color. The box is designed to not interfere with the clutch linkage or emergency brake system on the Broncos.