In 1971, the Tempest nameplate was completely retired and Pontiac promoted the LeMans nameplate to full-series status to identify all of its intermediate models, which still included the GTO. At the bottom of the line was the Pontiac T-37, previously known as the Tempest.
You'll find more info about it here:
Another way to look at it... 1969 Pontiac Had the Custom S, Tempest, and Tempest H.O.
1970 Pontiac wanted to change the Custom S... And the Car basic's stayed the same But a simpler name was added T-37 was aproved with the Tempest as its main basic car.
The Tempest was standard with the average Options.
If you wanted to add all the GTO options to a Tempest YOU had to order a T-37 and order each option you wanted And was NOT advertised because they wanted people to buy More GTO's
Then GT-37 option 70 1/2 was added to the T-37 Tempest line... Still Very under advertised until 1971
Then the 71 T-37 was now the Tempest and the GT-37 was an Option for the T-37 and the LeMans GT-37...
If you all are Junk yarding, Look for this missing links. A 71 4 door Post sedan T-37 with a 455 D port engine auto. PDB, radio and no other options. Never seen. Also 71 LeMans 4 dr Hard top with 455 D GT-37 with strips and A/C lots of options. Last seen in Texas. Both as Rare as the 72 GTO stationwagon's only 3 of those where made. I like the 72 GTO Post coupe 455 HO's more but still hunting.