1972 drastically reduced the engine options and power in American cars. My 454 corvette was a dog with 270 rated horsepower, and just sucked fuel. T tops leaked, build quality was horrible. 1975 was a further garroting. I worked in a GM Honda dealership as a Honda tech. 1975. If we ran out of Honda work and were offered GM warranty work, you would close your box and clock out. Honda 600s were better built than Bonneville Grand Broughams.
I have had several 70s Malaise cars. Most had atrocious build quality. After 4 of those full-size GM wagons, I gave up. Neat to see, terrible to own. The sedans were a little better. Those massive bumpers in 74-76 were like gangly appendages, seeking out all other automotive protuberances.
AIR (smog) pumps were (are) a complete scam. When emissions was measured in PPM, the answer was to introduce more air to increase the M(illions). Low pressure, high-volume pumps were to continue combustion of unburied hydrocarbons, they said, and feed O2 into the second oxidizing side of the cat, they said. Funny how when the standard changes to g/mi, AIR pumps vanished. Oh, improved emissions controls... uh huh. Went through emissions here 2x. 1x without the pump (duh, I should have pulled the idler and put the pump back), then with. Because they (used to) complete the visual after you were on the dyno rollers, I got the printout. Higher emissions (slightly) with the AIR pump. Probably due to all the other vehicles testing later the same day. G/mi makes AIR pumps worthless.