05/02/12 12:29PM Originals, Pontiac, Pontiac Firebird, Pontiac Firebird Trans Am, Pontiac SD-455, Pontiac Super Duty

Upcoming: Hemmings Muscle Machines examines Pontiac’s Super Duty of the ’70s

The somewhat abrupt demise of the American muscle car during the early 1970s has been well documented and long lamented, even today, as the U.S. automakers continue to build better and faster cars with the same V-8/rear-drive configuration as their forefathers. But as the 1970s unfurled and dark clouds gathered for fans of factory performance, Pontiac stood tall, defiantly issuing the Super Duty 455 engine at a time when all the other Detroit brands could offer was a leftover smattering of watered-down has-been heroes.

Pontiac’s Super Duty was not a de-tuned version of a previous 455, but instead, a new creation, featuring its own engine block and cylinder heads, in addition to many other internal details. Initially, the plan had been to offer the SD-455 in a variety of Pontiac models, including the newly redesigned A-body line, where it was to be an option in the GTO and Grand Am, and according to some sources, even in the Grand Prix at one point. But strife within the division brought on by managerial changes and the ensuing adjustment to strategy nearly killed the SD program completely. In the end, it was a Firebird exclusive, available as an option on both the Formula and the Trans Am for both 1973 and 1974. Even then, the relatively steep cost of the option along with some production delays kept many SD-455 cars from being built – a total of only 1,296 were produced, including both Formulas and Trans Ams for both years.

In the June 2012 edition of Hemmings Muscle Machines magazine (HMM #105), we take an in-depth look at Pontiac’s Super Duty 455 models as the subject of the issue’s Buyer’s Guide. To illustrate the breed, we’re highlighting the 1974 Trans Am SD-455 of father and son team John and Austin Marshall of Phoenix, Arizona.

Even among Super Duty Firebirds, the Marshalls’ Trans Am is a standout, for a few reasons. First, it’s a four-speed, which puts it in a small minority of SDs, despite the model’s racing aspirations. This particular T/A is also interesting because, beyond the SD option, little else was checked off – standard interior, standard Rally II wheels, no air conditioning and not even the iconic hood bird decal, which Pontiac treated as an extra, despite popular belief that all Trans Ams were so adorned. There’s not even a console between those basic black buckets, and the windows must be wound manually. The window sticker, which remains with the car, shows additional charges for the engine upgrade, an AM radio, a rear window defogger, which was required on all cars sold in New York state where the T/A was originally delivered, plus a charge for an upgrade to white-letter radial tires in place of the blackwall radials that the Trans Am’s standard “Radial Tuned Suspension” included. That’s it.

Speaking of those tires, they’re still present – you won’t find reproductions of Uniroyal Steel Belted Radials in any catalog today. They’ve managed to survive because this Trans Am has so far covered only 19,000 miles in its 38 years, and the most recently accrued have been traversed using a spare set of wheels mounting contemporary rubber. Needless to say, the Trans Am is just about all original, including the paint and decals. The Marshalls have been caretakers of the Trans Am since buying it from a collector in 1995, back when it had only 14,000 miles. Though they’ve only added 5,000 miles in 17 years, each trip has been relished, as Austin related. “I’ve driven the car occasionally, and I really like the feel of it – the long-throw on the shifter and the travel on the clutch, and the way the shaker responds to your right foot; no new car can provide that experience.”

For the Buyer’s Guide on Super Duty-powered Firebird Formulas and Trans Ams, check out the June 2012 issue of Hemmings Muscle Machines, on newsstands now and available at Hemmings.com.

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