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The T-tops that were part of the 1976 50th anniversary package joined the regular options list for 1977.
The ever-tightening California and federal emission standards contributed to the most confusing engine roster the Grand Prix had ever seen. Depending on the state to which a car was to be delivered, there might be a Pontiac-, Chevrolet-, or Oldsmobile-built V-8 under the hood, as there was a 49-state engine lineup and a California and high-altitude lineup.
The base GP engine for 1977 was Pontiac's new 301-cubic-inch (4.9-liter) V-8. It shared many basic block dimensions with an experimental 303 Trans Am race engine from 1969, though the new production powerplant was not nearly as beefy. Its deck was one inch shorter than its larger siblings. Connecting rods measured 6.05 inches versus 6.625 inches for its larger brothers. The bore and stroke measured 4x3 inches, respectively, and the pistons and connecting rods were shared with Pontiac's new 151-cubic-inch "Iron Duke" four.
The new engine shared the same three-inch main journal diameters as the 350 and 400 V-8s. The block, heads, and intake manifold were very lightweight castings, and the crankshaft only had counterweights on each end in the interest of weight reduction. Although the 301 was based on the tried and true Pontiac V-8, there were enough differences to preclude a great deal of parts interchange.
The result of the pound-shaving efforts dropped the overall weight of the 301 significantly. While the larger Pontiac engines tipped the scales between 640 and 675 pounds, the new V-8 came in at a very trim 452 pounds, about the same weight as Buick's 231-cubic-inch V-6.
The 301 produced 135 horsepower at 3,800 rpm, with 240 pound-feet of torque at 2,000 rpm. While the horsepower rating would only rank as mediocre for the current crop of four-cylinders, the power level of the 301 was similar to other 5.0-liter V-8 engines of the period and had the advantage of being lighter in weight.
Next up the option ladder was the "5.7 liter" V-8 engine. Depending on the time and plant in which a car was built and the zone to which it was delivered, the buyer might receive a 350-cubic-inch Pontiac, Olds, or Chevy engine.
There were a couple of reasons for this. The first problem was that the Pontiac 350 would not pass the stricter California and high-altitude emission standards. For those areas, the division substituted the Oldsmobile-designed 350. Since the Olds engines were cleaner running than the other GM V-8s, there was a great demand for them. The resulting shortage of Olds 350s meant that not even Oldsmobile had enough of them for its Cutlasses. In turn, Chevrolet's 350 began filling in for the Olds 350.
The top GP engine option for 1977 was the "6.6-liter" V-8, which was standard in the SJ. Again, depending on time and place of delivery, the actual engine could be the 180-horsepower Pontiac 400 or the cleaner-burning 185-horse Oldsmobile 403. (Like the smaller-displacement Olds V-8, the 403 was also in short supply.) The 455 was discontinued at the end of 1976.
Continue to the next page to read about the 1977 Grand Prix's sales successes.
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