Produced from 1967 to 1969 and usually reserved for Bonneville/Catalina’s, Prixs and other full-size/muscle cars (though we’ll touch on the exceptions to the rule shortly), the Pontiac V8 428 cubic inch (7.0 l) engine was an evolution of the 421 (a Nascar super-duty favorite) and its basic design. It even kept the same four-inch stroke as the 421.
Increased Bore and Horsepower
The bore was increased from four and 3/32 inches to 4.12 inches, which gave it a displacement of seven liters, and the engine produced 360 and 376 horsepower at 4,600 horsepower depending on the version when it was originally released. Improvements were made and by the end of its line produced 370 and 390 horsepower in both versions.
As we mentioned, the 428 was mostly exclusive to the Prix and Bonneville/Catalina—this was a result of GM’s strict internal policy limiting the engine size of midsize cars to 330 cubic Inches. Pontiac, however, would choose to sidestep that policy when it built the GTO. Many dealers often would install the model on GTOs and Firebirds for extra power.
The 428 is also distinguishable from its 421 counterpart by the “N” cast on the crankshaft (composed of much stronger iron alloys) as opposed to the 421’s Armasteel cast.
A Shift to Open Chamber Cylinder Heads for More Power
In the original 1967 version, the 428’s closed chamber cylinder heads had a 14-degree valve angle. However, in 1968 and 1969, this design was shifted in favor of open chambers. Because it was designed for larger cars, it had a tank that could hold 26 gallons. The engine had 472 foot pounds of torque, which is equal to 3,200 RPMs of pulling power. With some specialist modifications, that power could be improved.
An Enduring Legacy
The 428’s minuscule three-year production lifespan can be attributed to its replacement, the 455, which—like the 428 did with the 421—expanded the bore of its predecessor. The 428 always was intended to be a bridge between the 421 and the 455. However, despite its short production time, its popularity with performance enthusiasts and drag racers kept it alive much longer.
Revisit This 1976 Pontiac Trans Am from the World of Wheels Car Show
The owner of this newly restored 1976 Trans Am wanted to drive it, not show it at the 2017 World of Wheels Show. Ron from Vail’s Classic Car had to talk the owner into sharing this wonderful restoration with the public.
The restoration story is heart moving. The owner had a desire to restore her late husband’s hot rod. Now she sees him when looking at this beautiful automobile.
This Trans Am has had only one owner. As Ron puts it, it was definitely barn-fresh and dusty. It was a joy to restore this legend back to its original glory. But the restoration journey did have some challenges. Watch the video and learn the entire story.
Make Sure You Have the Right Insurance
You can’t get the insurance you need for your Pontiac GTO or classic muscle car just anywhere.
The truth of the matter is, Classic Auto Insurance offers specialized classic car insurance coverage you just won’t find anywhere else for your collectible car.
We offer tailored classic car insurance coverage plans that are as unique as your cars – coverage that helps you protect and pass on the legacy you’ve worked so hard to build.
Collector and Classic Car Insurance for Less
Whether the engine in your collector car is new or old, whether it’s a limited edition or custom made, it’s a valuable investment. Let Classic Auto Insurance customize a policy to fit your needs. We offer affordable, Agreed Value coverage for a variety of collector, classic and custom vehicles. Our friendly, knowledgeable staff can answer your questions and give you a quote on the spot. Call 888-901-1338 or get an instant quote online and see how we can help safeguard your dream car.
