The end, yes, in 1972 we almost see the end of the Firebird because of a 174 days long strike. The production was a disaster due to new laws imposed by the government too late and forced GM to destroy a large portion (over 2100 firebird and camaro) of its production. It was too late to send models to dealers and the 72 vintages could not be sold the following year because they are not in compliance with 73 the standards. Only 1,286 T/A have been built 828 with automatic.
The other important information concerning the engine power calculation. Until then, it was measured at the flywheel that did not consider peripherals such as the alternator, power steering, the transmission ... Now they are displayed in SAE net (power to the rear wheels) and taking into consideration everything that "steals" power. The only aesthetic change concerns grilles that becomes hexagonal.
We can also note the "front valance panel" is now plastic piece opposed to metal versions of the 70-71 models.