U.S. regulations were about to have a big impact on the 1974 MGB, through a combination of horsepower strangling emissions, and 5-mph bumpers, which would require no-damage on impact and had to be 20 inches off the ground to match U.S. specifications for much bigger cars. The MGB suspension was raised 1.5 inches, which threw off the car’s looks, while eliminating sway bars affected the car’s handling.

A catalytic converter and single Stromberg carburetor would appear in 1975 and performance would sink still further with eventual 0-60 mph times around 18 seconds and top speed of about 85 mph by 1979. Lower rear axle gears and overdrive gearbox at least attempted to make up for the lower horsepower.

Sales continued to be healthier than the cars, however, with 20,779 1974 roadsters sold. The stopgap bumper solution before the rubber nose appeared mid-year was to fit two big rubber blocks to the bumpers for 1974. Meanwhile, the 5807 rubber-bumper 1974 1/2 models, had the rubber nose of the 1975-80 MGBs, but still had the twin SU carburetors instead of the single Stromberg. The 1974 roadster was overwhelmingly sold in the U.S. with 18,007 of the 20,779 coming to the U.S. Almost all of the 1974 1/2 models came to the U.S. Meanwhile, the UK bought 2155 1974 rubber block models and 439 1974 1/2 rubber nose roadsters.

This year would see the last MGB GTs sold in the U.S., though they would continue to be made until 1980 for the UK. A total of 10,965 1974 GTs were built, almost evenly divided between the U.S. and UK. The 1974 1/2 MGB GTs are extremely rare and only 1637 were built with the rubber bumpers and twin SU carburetors.

MGB colors expanded into a new palette for the 1974 year, some quite unusual. Interiors were now Black or Autumn Leaf, as the ginger-toned Ochre was dropped. Vinyl interiors were fitted to roadsters, with horizontal panels while brush nylon was used for the GT. Once more the special order Black could have Autumn Leaf or Black interior.

A new color was Mirage Mauve, Teal Blue returned, Bracken Brown was also new, and Harvest Gold continued. Tundra Green was new, Blaze Orange continued but Aconite Purple was also new. Damask Red returned along with Glacier White, while the new Citron Yellow was alarmingly bright. Teal Blue, Bracken Brown, Aconite Purple and Glacier White had Autumn Leaf interiors. Mirage Mauve, Harvest Gold, Blaze Orange Damask red and Citron Yellow had Black interiors.

Prices for 1974 MGBs rose sharply, with the last chrome bumper roadsters rising to $4149 and MGB GT to $4495. The rubber bumper 1974 1/2 roadster actually cost less at $3925 but the chrome bumper car is preferred by collectors, since removal of the large rubber black makes the car look like earlier models.