The 1966-1969 Buick Riviera models saw record sales for Buick. However, by 1970 the bloom was off the rose, and all Buicks, including the Buick Riviera, took a dip in sales. The 1970 Buick Riviera turned out to be a disappointment to some, especially aesthetically.
This model, as well as the 1969 Buick Riviera, had been restyled under Buick's new studio chief, Donald D, Lasky. Not that he had much choice. GM's design vice-president Bill Mitchell decided, in a characteristic change of mind on his earlier Ferrari/Rolls-Royce theme, to make the 1970 Buick Riviera "more French."
Mitchell wanted Lasky to put some "Delage" into the marque. That notion accounted for the skirted rear-wheel cutouts, the heavier rear aspect, and the wide and, some felt, obtrusive sweepspear along the sides. "The 1970 Riviera," as Dave Holls puts it, "was not a happy car."
Buick did, however, launch the 455-cid V-8 in the 1970 Buick Riviera, an engine rated at 370 bhp, with an axle-wrenching 510 lbs/ft torque. The 400 and 430 versions of this engine were now history as the 455 became the only big-block Buick available. Unlike Pontiac and Oldsmobile, which also had 455s, Cliff Studaker's strategy with Buick's engine was to give it better breathing through bigger valves.
He did this, not by stroking a smaller version of the engine as Pontiac and Olds had done, but rather by giving it more bore. Studaker left the 430's stroke at 3.9 inches but bored it out to 4.313. The extra bore, combined with the domed combustion chamber, allowed bigger valves than Buick's competition and also gave Buick an edge in meeting ever-tightening emissions standards.
GM's horsepower ratings in that era were more or less "formula," meaning A-cars couldn't advertise more than 360 bhp and B-cars had to stay under 370. So while an identical 455 Buick V-8 went into, say, the A-body's 1970 GS-455 and the 1970 Buick Riviera, the former listed this engine at 360 horses while the Buick Riviera got a 370 rating. Both shared the Buick Stage I high-lift cam, stiffer valve springs, big Quadrajet four-barrel carb, cold-air induction, and low-restriction dual exhausts.
The 1970 Buick Riviera model marked the last of the second-generation, 119-inch-wheelbase Buick Rivieras. Due in part to a soft economy, sales of the 1970 model fell precipitously, and they only kept heading downhill after the introduction of the controversial 1971 "boattail" design. But that's an altogether different car and a different story.
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