1970

• The 1970 GTO displayed the car's considerable weight gain from previous models, but it remained a striking, sporty car with a restyled front and rear, quad headlamps and an Endura front bumper. Pontiac's huge 455-cubic-inch V-8 became part of the GTO engine lineup. The 455 featured a Vacuum Operated Exhaust package that opened the exhaust system with the pull of a knob to add more kick. The GTO came either as a standard model or as the high-performance The Judge. It sat on a 112-inch wheelbase. Its power options were the 400 V-8 that developed 350 horsepower, the 400 Ram Air III that wielded 366 horsepower, the 400 Ram Air IV that delivered 370 horsepower and the 360-horsepower 455 that provided 500 foot-pounds of torque. The 400 Ram Air II achieved zero to 60 mph in a flat 6 seconds, and the quarter mile in 14.7 seconds. The Judge featured Ram Air forced air induction, blackout grille, T-shift four-speed manual transmission, graphics and badging.
  
  

1971

• The model year 1971 marked the end of the muscle car era. The 455 remained the standard powerplant, but Pontiac began downsizing horsepower ratings. Pontiac again restyled the body with a bigger grille and extending front bumpers. The 400 V-8 in 1971 developed 300 horsepower, while the standard 455 saw its horsepower drop to 325. A High Output 455 offered marginally better horsepower at 335.
  
  

1972

• The approaching doom of the GTO was evident in 1972, when the GTO lost its nameplate and became an option package for its cousin, the LeMans. The Judge disappeared, and Pontiac discontinued the convertibles. Pontiac continued its slash-and-burn campaign to reduce horsepower, as the muscle car era finally came to an end. The 400 V-8 developed only 250 horsepower, while the 455 garnered 300.
  
  

1973

• The 1973 Pontiac GTO underwent yet another redesign to accommodate new government safety regulations, with a heavy front chrome bumper. It also featured a sharp, angled nose. The LeMans GTO's horsepower dropped again, with the 400 producing just 230 horsepower. The 455 developed 250 horsepower. These engines could not break the 15-second barrier in the quarter mile run. Production dropped to 4,806, compared to 40,149 built in 1970.
  
  

1974

• The Pontiac GTO went out with a whimper, not a bang, in 1974, as it became an option for the compact Ventura hatchback and coupe. For the model year, it received only a 200-horsepower, 350-cubic-inch V-8 engine. It was the only model year that its engine was smaller than 389 cubic inches. The 350 powered the Ventura GTO to 60 mph in 7.7 seconds and the quarter mile in 15.72 seconds.