[chiphead]

Big one on left looks like a 70 GTO alternator bracket, but not quite. It also doesn't look like a '71-newer Pontiac PS or AC compressor bracket.
I'm guessing chevelle alternator bracket.

[srmmmm]

Rear bracket for power steering pump on the right. A/C compressor bracket for Chevrolet small block on the left.

[LStathas]

Originally Posted by srmmmm

Rear bracket for power steering pump on the right. A/C compressor bracket for Chevrolet small block on the left.

Thanks, SRM. I was thinking it wasn't Pontiac too. Crazy how we end up with random stuff like this over the years. I never owned a SBC.

[Elarson]

I agree on the right one being PS pump.
Left one looks like catalytic converter bracket from '70s Firebird

Eric

[P@blo]

Originally Posted by srmmmm

Rear bracket for power steering pump on the right. A/C compressor bracket for Chevrolet small block on the left.

Good eye sir! I have an original 80 SBC sporting that same bracket. And I agree on the PS pump bracket everyone else spotted.