Okay, January 2016 edition of The Judge clarifies the new Camaro classes for AACA.
34G is First Gen, 67-69
34H is Second Gen, 70-81
34I is Third Gen, 82-present (In AACA terms that means to 1991 this year.)
All Camaros, except for those in DPC, HPOF, or High Performance, will move to those classes.
The changes will not affect a car's current or future awards.
The VP of Judging says they have expanded High Performance class to include more of the 67 through 81 cars.
I think that means Zs will finally be listed as HP.
The good news here is that Camaros will now have their own classes.