The Boss Mustang is an iconic muscle machine that any car-guy worth their salt knows about. With the timeless look of the Mustang and the power of the Boss 302 cubic-inch powerplant under the hood, they were awesome cars then and have become quite the collector item today. Although a Boss-style build never landed production in the Bronco, just one prototype was produced.

This prototype was the realization of a dream thought up between Kar-Kraft and Bill Stroppe. They wanted Ford to make a high-performance version of their new Bronco. Kar-Kraft built the Bronco and there is even a picture from 1969 of the Boss Bronco outside the Ford styling building to prove it.

Every angle of this prototype Bronco emanates the iconic Boss style, with the caveat that it’s been applied to all-terrain vehicle!

While this Bronco obviously differs from the Boss Mustang in that it’s an SUV rather than a car, it also differs in that it has a 351-cube Windsor under the hood rather than the standard Boss 302 cubic-inch engine.

The Boss Bronco prototype was built with the styling and preferences in mind of the head of Ford at the time, Semon “Bunkie” Knudson. It was actually Bunkie that ordered the Boss Bronco and would have been able to approve it for production.


In addition to the blueprinted 1969 GT350-spec 351 cubic-inch engine the Boss Bronco prototype also features a few other noteworthy options. It features a high-performance C4 automatic transmission, 4.11:1 geared limited slip differentials (front and rear), Stroppe dual shocks, and a Stroppe power steering conversion. It also came with a Stroppe padded roll bar, Stroppe rear fender flares, a Cougar Eliminator hood scoop, and 10-inch wide chrome wheels. I bet you wish this thing was put into production almost as much as we do!

Bunkie Knudson’s favorite color was yellow, so they painted to Boss Bronco that color with his tastes in mind.

So what happened to the Bronco after Bunkie left Ford Motor Company? Sometime in late 1970 Kar-Kraft and Ford got into a dispute over the billing for the Bronco that caused Ford to pull their work from Kar-Kraft, causing them to go out of business. In the beginning the Bronco was marked as unsalable and to be crushed at the end of the project, but somewhere in that mess it escaped Kar-Kraft by sale in the hands of either a Kar-Kraft or Ford employee.

The SUV was converted from a base unit in only nine days at the Kar-Kraft building and was the first Bronco fitted with an automatic transmission.

The Boss Bronco decals were removed and it became just a regular yellow Bronco. It was lost and disappeared. Everyone knew that one was made, but nobody knew where it was — or even if it still was at all!

Boy are we glad this beauty didn’t see the crusher!

How the Bronco was discovered is nearly as interesting a story as the Bronco itself. While writing a new Kar Kraft books, the author, Wes Eisenschenk, received an inventory sheet from Kar Kraft from 1969. When he was searching some of the serial numbers in a DMV search, the one that came up was the Boss Bronco, and it had recently changed hands.

It was sold on eBay by the daughter of a man that had owned it for decades. They had no idea that it was anything special, to them it was just a hot-rodded yellow Bronco that they called the “Bumble Bee Bronco.” So when Wes found out about it, he got in contact with the new owner and bought it.

The SUV is completely unrestored. It was painted once, but the interior and drivetrain are completely original. It has no rust and still has the original finishes underneath and the Kar Kraft installed shifters installed. Everything down to the original carburetor and exhaust are still on it. It’s rare to find even just a plane-jane Bronco in this kind of shape, so the fact that this Boss Bronco survived in this condition is nothing short of a miracle.