The exterior of the extremely limited production Mustang Boss 429 is surprisingly clean—particularly considering that competitors from Pontiac and Oldsmobile (among others) were searing eyeballs with wild stripes, scoops, and wings. To be fair, the Boss 429 does sport a scoop and rear wing, but they’re relatively restrained. The only real indication from the outside that this isn’t a normal Mustang is the front fender script proclaiming it a “Boss 429.” Why does this Mustang pack such a huge motor when the Boss 302 was a perfectly acceptable muscle car? The answer is NASCAR—to homologate the 429 for use in NASCAR Torinos, Ford made the interesting choice of placing the engine where it didn’t quite fit—in the Mustang’s tight engine bay. Ford outsourced assembly to Kar Kraft, who seriously modified the front end, spreading the front suspension towers (incidentally increasing the front track), relocating the battery to the rear, and redoing the engine mounts. The goal from the get-go was simply to OK the engine for NASCAR duty, and so while the 375 horsepower engine wasn’t down on power, the overall package’s frightening expense didn’t help sales numbers any. However, rarity has been a boon for Boss 429s—with less than 2,000 made over two production years, the big-engined Ford brings outsized cash at auction.