What was bolted here?

[1967Z28]

It's from a '68 Camaro. The square hole holds the loop bracket that restrains the two heater hoses going from the heater core to the engine. The black area in the lower right of the picture is where the a-arm flap would be.

The holes may be for a NOx smog control box that used to get put on CA cars back in the '70s but those usually got mounted on the firewall.

[67since67]

Originally Posted by 1967Z28

The holes may be for a NOx smog control box that used to get put on CA cars back in the '70s but those usually got mounted on the firewall.

I removed this one from a SoCal '67 396 Chevelle decades ago, it was mounted on the firewall. The bolt spread is 2 1/4", other boxes may have had a wider spread??
A cool can would likely have been more horizontally mounted? Fuel pressure regulator?