As John and Sue Douglas of Brandon, Florida, motor into the driveway, I notice how sedate the 351 4V H.O. sounds. Outside of the solid lifters and a nice burble from the slash-cut tips, the Mach 1 has all the makings of a 351 4V of much plainer origins. But this isn't a 351 4V hydraulic-lifted engine; it's one of the last of the muscle-bound Mohicans to stride out of the Dearborn River Rouge plant-at least until the power program began to roll again in the early '80s. This Mach 1 bears the engine that almost wasn't; in fact, if you wanted one at the beginning of 1972, you were out of luck. According to a '72 Car and Driver article on the H.O., "The accountants can't justify that kind of car [high-performance] anymore and they've let everybody know it." This also led to the very limited number of 351 H.O.s that were produced. How limited? For all models, 398, and yes, the H.O. was available in any Mustang body style. The fact of the matter is, 19 hardtops, 366 SportsRoofs, and 13 convertibles were sent out the door in 1972. So on a rarity scale, we'd have to say the H.O. is probably the rarest engine to make its home in the Mustang.
What was an H.O.? Basically the H.O. was a detuned Boss 351. We say detuned because the compression ratio was cut from a lofty 11.7:1 down to a more regular, gas-friendly 8.8:1 ratio, according to the same Car and Driver article mentioned earlier. The article went on to report that the cam was retarded four degrees to reduce emissions-just like its little brother, the 351 4V. Otherwise, the engine and the driveline is all Boss. And just because it was short on cam and compression don't think Ford put A/C in the mix; there was still the 3.91:1 Traction-Lok axle out back. Even the four-speed was mandatory; though for 1972, the shift arm changed to a round shaft and the handle to a black ball. The mandatory gauge package that kept the Boss owner informed was no longer part of the H.O.; which brings us to John and his Medium Bright Yellow Mach 1
To say that the Mach is a stripper would be a shame, because under the hood resides the aforementioned H.O. and all the goodness that goes with it. But amenities aren't part of the car's makeup. The option list is Spartan, to be completely blunt. There are exactly four options outside of the H.O. and its mandatory list of must-haves, such as four-speed, power disc brakes, 3.91:1 rear gears, and a special competition suspension. We say special because the 351 H.O. shared suspension components with the 429 SCJ four-speed and the Boss 351 of the previous year. This gave it a larger rear sway bar and different spring rates over the 351 4V with competition suspension. The other options we alluded to? The Mach 1 package, interval wipers, an AM radio, Magnum 500s, and nothing else. Even the interval wipers were a bonus that never showed up on the invoice.
John has a long history with '72 Mach 1s since he campaigned one in NHRA competition for many years before giving it up for a T-bird. Then somebody put a bug in his ear for this car. But John kept mum for a while, let it sit, then finally he bit. Or was he bitten?
"The car was really rough, especially after we started digging into it," said John. The "before" picture, according to John, really doesn't show just how bad the old R-code was. "Nothing was left untouched, the interior was trashed, and there are some base-model pieces we're still looking for," he said.
We're confident he'll find them too. Yellow fever can make you that way. How do we know? 'Cause we think we have a case of yellow fever too.