with aluminum block engines. Although Buick and Olds shared the same basic engine design, both divisions used different cylinder heads, camshafts, carburetors and compression ratios. The 215 V8 was also available on the Pontiac Tempest for 1961 and 1962 and used the Buick version, but very few Tempests were so-equipped. For 1962, Buick introduced a new 198 cubic-inch V6 engine for the lower-line Special models in order to allow for a lower base price. That V6 shared many parts and dimensions with the aluminum V8 engine but featured a cast iron block. Oldsmobile introduced a turbocharged version of the 215 V8 in mid-1962 for a special performance version of the F-85/Cutlass called the Jetfire. This engine was among the first production turbocharged engines ever offered in a passenger car, the other being the Chevrolet Corvair's turbocharged flat-six engine introduced simultaneously for the Monza Spyder. The Olds Jetfire turbocharged V8 featured a four-barrel, 10.25 to 1 compression and was rated at 215 horsepower - one horsepower per cubic inch. The Pontiac Tempest came standard with a 195 cubic-inch slant four-cylinder engine - then the only U.S.-built passenger car with such an engine. The Tempest four was really created from half a 389 cubic inch V8 block used in the standard Pontiacs. This engine, available with one- and four-barrel carburetion offered horsepower ratings ranging from 110 to 166. The Tempest also used a rear transmission, or transaxle to permit four wheel independent suspension, a flat floor, eliminating the driveshaft hump, for improved interior space, while the Buick Special and Olds F-85 used a conventional front engine/front transmission drivetrain, albeit, with a two piece driveshaft. The Tempest also used an independent rear swing axle suspension similar to the rear-engine Chevy Corvair while the Buick and Olds compacts featured a conventional rear coil spring suspension. For 1963, Pontiac replaced the Buick-sourced 215 aluminum V8 with a Pontiac built 336 cubic-inch V8 as the top power option for the Tempest. No one seems to know why the 326 of 1963 was called a 326, because the true displacement was 336. This 326 was based on the big Pontiac's 389 V8 and shared many of the larger engine's dimensions and components with horsepower ratings of 260 and 280. The '63 326 Tempest/LeMans served as a testbed for the 389-powered 1964 GTO that would be based on a larger and more conventionally engineered Tempest introduced the following