The mid-sized LeMans G3 was on the “A” body platform, the same as the Tempest for the 1968 model year. The body styles were a two-door coupe, a convertible, a four-door sedan, a two-door sedan, and a four-door station wagon.
inch (5.7L) replaced the old 326 base V8 engine in 1968. The 326 used existing Pontiac technology, increased the stroke length with a 400 series crankshaft, enlarged the bore from 2.72 inches to 3.88 inches, which actually turned it into a 354.74. The 326 was actually a 336, and the 350 was actually a 354, it’s anyone’s guess why Pontiac chose to fudge the numbers.
However, an owner could have had the new engine in either a two-barrel carburetor version producing 260hp (193.9 kW ) or the four-barrel version developing 325hp (342. kW). Pontiac reworked the engine for ’69 with a new cam. It also used #48 big valve heads like the Ram air 3 and now produced 265hp (197.6 kW) or 330hp (246 kW), respectively. This was the last year a high-performance version of the 350 was on the option sheet.
A revision of the Pontiac mid-sized lineup in 1970 downgraded the base LeMans to replace the Tempest Custom, and it came as a two- or four-door pillared sedan. The most uptown LeMans Sport was available in all the same body styles as the previous year, but bigger engines usually reserved for the GTO were available for the lesser LeMans and the Tempest. A 400-cubic-inch (6.55L) V8 engine was now on the roster and produced 265hp (197.6 kW) with the two-barrel or put out 330hp (246 kW) with the optional four-barrel, which included dual exhaust pipes.
Later in 1970, Pontiac added a budget-priced hard-top coupe called the GT-37 to the model list, and according to Pontiac, the lowest cost hard-top available from GM, but this was a few weeks before the Chevy Chevelle duplicated it and at a lower cost. For the GT-37, a package was available for the LeMans or Tempest that added a three-speed floor shift, tuned suspension, striping, and other trim to appeal to the young crowd that couldn’t raise the cash to buy a GTO. The package could include any of the engines from the base 350 two-barrel to the 400 four-barrel. Pontiac discontinued the high-output 350 four-barrel for the 1970 model year.
The LeMans is the only Pontiac intermediate for 1971 that included the GTO option under its umbrella. The Tempest nameplate retired, making the Pontiac T-37 the entry-level LeMans. All the engines were detuned that year and ran on regular gasoline, but for 1971, it was possible to power the LeMans with the 455-cubic-inch (7.5L) V8 as a base with a four-barrel producing 325hp (242 kW) or an HO version developing 335hp (249.8 kW).
In 1972, Pontiac rebadged the T-37 base as the LeMans pillared coupe. The top-of-the-line luxury LeMans had a much plusher interior than the lesser units and was available as a hard-top sedan or a coupe. The Sport Coupe was a choice that included the Strato bucket seats and the same plush LeMans interior fit into a hard-top or coupe model. The GTO now came with a power option pack for the LeMans, and the previous GT-37 option remained the same but was now the LeMans GT option.