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1973 Pontiac GTO SD-455 Road Test from
CARS magazine, April 1972


The illustration at right of a turned-on '73 GTO was on the cover of "CARS" magazine April 1972. Car won the "TOP PERFORMANCE CAR OF THE YEAR AWARD", partially based on the info that the car would be available with the SD-455 engine. Pre-production cars tested with the Super Duty engine were hands-down hottest performance cars coming out of Motown.


Let's read on now, and see just how the 1973 GTO REALLY was...



Pontiac invented the supercar in 1963, and ten years later emerges as it's exclusive producer.

The new GTO is the epitome of the tough street machine which has just about disappeared from Detroit's new car lineups. Moon-style hubcaps are golden oldies. Louvered rear quarter windows, NASA hood scoops and body styling are modern updated features. In thirteen years of selecting "Top Performance Car of the Year" candidates, flogging them on the open road and under controlled test track conditions and finally selecting the Top Eliminator, never has our job been easier. It is the first time that one car has emerged head and shoulders above EVERY other entry. In fact, you might even say it wasn't a contest. Pontiac came, saw, and conquered. With its all new GTO, Pontiac challenged all of Motown to a supercar showdown. And, when the smoke had cleared, it appeared that the GTO once again was King of the Street.

The supercar may be dead and buried in other quarters but, for some strange reason, the message hasn't been received in Pontiac, Michigan. In an era of decreasing performance, marginal styling and an overall "ban the bomb" attitude, Pontiac has gotten its act together in one of the most exciting, genuine performance intermediates ever to come out of the Motor City. The 1973 GTO, which is better than the original Tiger in every conceivable way, is alive, well and available from your friendly Pontiac dealer. At a time when every other manufacturer has forgotten the enthusiast/performance car market, Pontiac has combined the best features of the 1964-'67 GTO with the most modern technology and safety features to produce the all new GTO, our choice for "Top Performance Car of the Year" honors.



The all new GTO is what it is because of a group of forward-thinking product planners and engineers who spent untold hours surveying the demographic breakdown of older GTO buyers and of the status of the current marketplace. What they learned, basically, is that there were two groups of GTO buyers: young adults who were primarily interested in performance and older affluent professionals who wanted the performance image with all the comforts of a luxury car.

The net results of the survey netted the market place with a Grand Am for the luxury/performance car buyer and a genuine supercar in every sense of the word for the enthusiast. The GTO was then positioned for the marketplace with an "as low as possible" base price to attract the young buyer, and with a great power to weight ratio, and suspension that would mesmerize the buyer interested in no nonsense handling characteristics and a good, solid base powertrain. There you have the 1973 GTO.



Super-Duty 455 engine differs from common, garden variety 455 in all important internal and external areas. Individual runner manifolds, forged steel rods and forged aluminum pistons, super trick lube system with provisions for dry sump are SD tricks.

For 1973 the GTO remains as an option and not a car. The option is available on the LeMans and LeMans Sport Coupe two door Colonnade hardtop and is fitted with all the goodies that were responsible for the image created by the original GTO. There's a blacked out grille; dual hood scoops; optional (functional) Ram Air; super suspension; GTO identification; Moon styled hubcaps with G-60 black tires; chrome duals and seven-inch wheels. The base engine is the 400 four-barrel but you can option the supermarket 455 inch four barrel and the King of the Street Super Duty 455. There's also an option list that immediately recalls the good old days. And, it's all legal eagle and insurable.

New option this year is NASA scoop treatment which is standard on the GTO. Coupled with the optional ram air package the scoops direct cool fresh air to the Quadrajet four-barrel. It's a nice package with the Super Duty 455 engine. Head Turning Power is unreal!


The optional 455 inch four barrel engine isn't much of a performance engine and actually offers little more for the enthusiast than the base 400 incher. The SD 455, however, is something else. It pumps out 310 net horsepower, runs on 91 octane fuel (it runs much better with timing kicked up and the tank filled with Sunoco 260!) and passes all federal and state emission and noise laws. And, it's actually no less economical to operate under normal driving use than the consumer oriented 455 four barrel engine. It can be had with air conditioning, full power, 3.42 limited slip rear and a choice of M-20 four speed or three speed Turbo Hydro transmissions. Features that make the SD 455 a genuine performance engine include four bolt main caps; screw in oil plugs; provision for dry sump lubrication; nodular iron crank; forged steel rods with 7/16-inch bolts; forged aluminum pistons with high rev rings; Heavy Duty oil pump; flow bench designed heads; high lift cam with big valves; big headers and exhaust pipes and a revamped Quadrajet intake system.



Even on a wet road surface the GTO is an outstanding handler. Now suspension is the firmest ever offered in a production intermediate and really gets the job done. Much care must be exercised on wet roads because of aquaplaning effect of 60 series tires.

When the engineers designed the suspension for the GTO it was almost as though they had our very own Joe Oldham in mind. Joe has little use for anything other than the ultimate handling vehicle and he doesn't care how harsh a car rides as long as it'll go around a handling course or a skid pad with only minimal traces of sway or roll. Joe likes his cars hard riding, positive handling and totally predictable. In most cases, the "optional-optional" factory suspensions aren't stiff enough for him. The GTO receives the Oldham Seal of Suspension Approval! It isn't as harsh as you might think, but there's little doubt that the GTO can take the highest lateral G loads possible in a car of this size and weight. If you are looking for more of a compromised ride, the Grand Am would be a far better choice than the GTO.


The new GTO "OM" (Oldham Maximus) suspension makes use of a 1 1/8-inch front sway bar and a one-inch rear bar. The older cars had a one incher up front backed up by a 7/8 inch rear bar. The thinking here was to keep the standard spring rates and control the roll stiffness via the use of front and rear stabilizer bars to maintain a reasonably good ride. Harshness has been dampened but not enough to make the ride appeal to the pseudo enthusiast's tastes. Super fat 15-inch 60-series tires are used for both appearance and for maximum traction. The engineers also feel that 60 series tires offer more cornering power with the GTO's suspension than do radials. Radials are used to a fantastic advantage with the calmer Grand Am suspension, but the engineers feel that they don't work as well as the 60 series tires with the GTO suspension. Radials are also more expensive and do not fit in with the basic GTO marketing concept.

The 1973 GTO offers enthusiasts everything the golden oldie GTO did, plus all the new technology gleaned since those cars were on the drawing board. You have to pay more for the '73 version, but we don't believe this will prevent enthusiasts from signing on the dotted line. It's the most refreshing car to drive since solid lifters, Holley carbs and real engines were "discontinued until further notice." We believe Pontiac's GTO has far surpassed its ontogenic beginning!



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