With all the focus on the Boss 302 Mustang released by Ford, it can be easy to forget about the Big Boss. We mean of course the Boss 429 Mustangs, boasting enough big-block power and torque to tear a tree stump out of the ground. With today’s focus on fuel economy though, it’s unlikely that we’ll see Ford bring back gas-guzzling big-block motors anytime soon.

Back in August, the guys from the world-famous Galpin Auto Sports unveiled concept sketches for a widebody Mustang inspired by the 429 Mustang of yesteryear. It will be auctioned off for charity at next months Barrett-Jackson auction in Scottsdale, Arizona.

Galpin didn’t turn to some body kit for their widebody bad-boy, but rather fabricated a custom widebody from metal for this particular Mustang. The widebody gives this Mustang a very mean, muscular look, like its ready to pounce. The Boss 429 inspiration can be seen across the whole Mustang, from the hood and side scoops to the chunky butt and unamused front fascia. We’re pretty sure the original Boss 429 didn’t have 22-inch wheels in back and 21-inch wheels up front, but whatever, right?

The original Boss 429 was rated at 375 horsepower, although word on the street was that they made closer to 400 or 500 horsepower. The Galpin Auto Sports Mustang makes over 700 horsepower thanks to a Ford Racing supercharger. Galpin will auction off this Mustang, with the proceeds going to benefit St. Jude’s Children’s Hospital. A great car for a great cause. What do you think it will bring at auction?