Looking from the outside, you'd be hard pressed to tell the '71 from the '70, as the visual clues are minor. The one visual clue is the soon to be trademark of a Trans Am- lettering theengine displacement on the shaker. Perhaps Pontiac wanted to let everyone know there was anew and torqueier engine residing beneath the shaker.

Nineteen-Seventy-One marks the year in which the engine most associated with the TransAm made it's debut. The 455. This new engine was the 400 stroked .46 inches (to 4.21 vs 3.75inches) and offered a bit for more torque - 480 gross lb/ft of torque to be exact. To be more exact, the new net torque ratings were 410 lb/ft @ 3600 prm. The increase meant theengine was now "undersquare" , meaning the stroke was longer than the diameter of thecylinder bore (4.12"), henceforth a 5500 rpm redline. The engine, coded as YE or YA when coupled to an automatic and WL or WC when installed infront of a 4-speed, featured a four-bolt main bearing block and aluminum intake manifold.Thenew engine was not without compromise, however, as the horsepower numbers dropped off a bitas compression ratios took the first plunge into mediocrity. In 1970 the 400 V8 featured a 10.5:1compression ratio, while for '71 the ratio dropped to 8.4 as the auto makers were succumbing tothe pressures of the insurance companies and preparing for the inevitable switch to unleaded fuels.

Since the 455 was an undersquare engine, Pontiac engineers used lighter parts in thereciporcating assembly to reduce mass, therefore relieving stress. Each piston lost 1 1/2 oz eachto reduce the mass. To make the engine stronger, the crankshaft main bearing journal diameterwent from 3.00" in the 400 to 3.25" in the 455. All crankshafts were cast of nodular iron rather than standard cast iron for increased toughness.

No longer were there any "ram air" references, as this engine performed it's last service of duty the prior year. On the bright side, the 455 posted good horsepower numbers, still producing 335 gross hp at 4800 rpm or 310 net @4800 and the aforementioned 480 lb/ft of torque at 3600 rpm. A new cylinder head casting, #197 replace the mighty "Ram Air III and IV" cylinder heads. The head was unique to the 335 hp engine, as the "other" 455 engines had the #66 casting. The camshaft lost a great deal of lift in the 400 to 455 switchover. On the Ram Air IV 370hp engine, the valve lift for the intake/exhaust valves were .527/.527 inches respectively. The 455 used the part number 9779068 camshaft, the same as the R/A III, and it developed .408/.406 inches of lift respectively. Also missing was 20-degrees of intake and 18-degrees of exhaust valve duration. On the plus side, the 455 H.O. in the Trans Am still reatined screw-in rocker arm studs.

Atop the engine sat a cast aluminum intake manifold with a separate cast iron crossover for exhaust gases recirculation. By making this a separate piece, it didn't take owners long to remove this as to increase power. A Rochester Quadrajet 4-bbl carburetor sat below the shaker/air cleaner assembly.

The H.O. engines still had the desirable "round" exhaust port rather than the "D" shaped ports of mainstream 455's. Another desirable quality of the 455 H.O. engines was the select fit porcess during line assembly of the engines. This allowed for closer tolerances resulting in a nearly blueprinted engine - direct from the factory.

A conventional distributor was still used, and it carried pn 1112073 and ignited AC R-46Sspark plugs set at .035"

Three transmissions were offered, the standard M13 three speed HD manual, the RPO M40 TurboHydraMatic 400, or the close ratio four speed manual RPO M22 rock crusher transmissions. The gearboxes were ideally matched for the generous levles of torque the 455 could supply. At the rear of the car, the famed GM 12-bolt rear end was no more, replaced by a bit less sturdy 10-bolt. Three axle ratios, 3.08, 3.42, and 3.73:1 were offered, depending on transmission and equipment choices.

The shaker scoop was still functional as the exterior engine noise level standards hadn'tlegistated this neat feature out of production. As on the '70 models, the solenoid activatedflapper and this was still an axiliary source of cooler air as the air cleaner ingested air normally through dual snorkels.

The rest of the outside was carryover for the most part. Color choices were still limited tocameo white with blue stripes and shaker or the lucerne blue with a white stripe/shaker combo.The engine displacement decal were the same color as the exterior. The poly cast honeycomb wheels made their debut in '71 and would remain popular until replaced by the aluminum snowflake of 1977. These wheels were quite deceptive as they certainly had the look ofa "mag" wheel. Nothing could be further from the truth however, as these wheels were merelysteel 15" x 7" steel wheels with a ruberized metallic silver honeycomb center (the first compositewheel?).

Inside, the T/A received the high-back bucket seats. These seats would remain in basic formuntil the advent of the all-new 1982 models. The only other seat style offered during the 71-81production run were the Recaro buckets offered in the '81 NASCAR edition. The highback style if the seats were very much in vogue in the early seventies. They gave a wrap aroundfeel to the interior, while being somewhat comfortable.

Somewhat is stressed because for some reason, Detroit had a problem with building carswith adjustable seat backs. (the Chevrolet Camaro did have an optional two-position seat backadjuster). The seat was very upright, but this was almost necessary with the formula steering wheel. Matching up to the front seat center console was a rear seat console whichextened from the rear of the front one and filled in the otherwise carpeted void of the rear seats.Pontiac introduced an option that proved to be ahead of it's time, a cassette tape player.In a world where the 8-track was king, the cassette player was a much undesired option. Ipersonally have never seen one in a Trans Am (or Firebird), and my guess is this would be a rare piece. Another new option, an in car rechargable flash light could be had fora mere $12.64.

The base price increased to $4595.00, a $290.00 increase over the 1970 version. Productionof the Trans Am dropped to a mere 2116 cars, nearly a 50% decrease form the 3196 1970models built. Automatic's outnumbered manuals 3-to-2 with 1231 buyers opting for the turbo400, and 885 going for the "rock crusher"

1971 was certainly a pivotal year to the Trans Am, with legislators pushing for clean air andless horsepower, many feared the newly designed Firebird and specificly the Trans Am would bea short lived "nice try".