It's located on the passenger side of the engine compartment attached to the frame below the alternator. I believe it is some kind of splash guard to prevent water, etc from getting to the alternator or smog pump. It is made out of some kind of fiber board. Thanks!
The ones on my 72 are rubber, and they can be bought new on Ebay most of the time. I imagine rubber ones for a 73 would be an exact match.
Strange how things like this hang on for years but how many new cars you see running around dragging their splash panels on the ground.
