If there was an equivalent of a Victoria’s Secret catalog for engine parts, the Boss 429 engine would seize its rightful place on the cover. Blown flatheads needn’t apply. With its gloriously wide cylinder heads and beautifully scalloped valve covers, its visceral appeal and visual presence lingers somewhere between exotic and erotic. The only way a Boss motor could look any cooler is if it were topped with a fistful of Webers breathing through individual polished aluminum throttle stacks. Thanks to its hot shape, scarcity, and storied history in NASCAR competition, the mystique surrounding the Boss 429 in Ford circles makes grown men do funny things. Todd Miller of TM Enterprises is one of those guys, and his love of the fabled Boss platform inspired him to start up an aftermarket operation dedicated to keeping the Shotgun motor alive and kicking. To show what a modern iteration of a Boss is capable of, he built one to run up against some of the most extreme street motors in the country at the 2010 AMSOIL Engine Masters Challenge.

Boss or Bust
In the Blue Oval camp, the love of the Boss 429 runs deep largely because so few of them were ever built. After NASCAR banned the FE-based 427 Cammer motor in 1965, an elite cadre of defiant Ford engineers went back to the drawing board and whipped up the Boss 429. Like the Chrysler Hemi it was designed to chase down on the high-banked superspeedways, the Boss featured a somewhat standard short-block topped by hemispherical cylinder heads packing massive 2.400-inch intake valves (2.280-inch for street variants). Essentially a fortified 385-series big-block bottom end with a wicked set of heads, the Boss 429 started out like gangbusters, with Fords powering the 1969 Daytona 500 winner along with six of the Top 10 finishers in that race. Unfortunately, Ford determined that the Boss 429 program was too expensive after just two seasons of competition, and killed it off after the 1970 season.

Per NASCAR homologation rules at the time, Ford had to build a minimum of 500 Boss motors in street cars, most of which landed in Mustangs. Since the Boss 429 only competed in the Grand National Series for two seasons, the number of street variants still in existence is extremely small to say the least. That’s where companies like TME step in. Hot rodders discovered long ago that the Boss Hemi heads will bolt right up to a standard 429/460 block without much modification. Miller says that other than the addition of four-bolt main caps, priority main oiling system, beefier rods, and forged crank, the Boss 429 short-block isn’t all that different from a standard 385-series big-block.

For Ford enthusiasts interested in a Hemi-headed conversion, the problem has always been tracking down the heads, so several years ago Miller decided to make his own. Although his day job as a foundry equipment builder keeps him plenty busy, Miller found the time to design a set of all-new Boss 429 Hemi head castings. The AMSOIL Engine Masters Challenge served as a perfect opportunity for Miller to showcase his heads and exercise his passion for the Boss platform. The only thing I was interested in building for the EMC was a Boss motor, he says. It’s probably not the most practical choice for this kind of competition, but for me it was between building a Boss or building nothing at all. All Boss fans like the exotica that comes with these motors, and I’m no exception.