Help ID this part!

Luke, that's a smog pump. It basically sent compressed air down to the cat to help burn off emissions.
Mopar used them briefly and got away from them quickly.
As you can see, someone all ready cut the belt, that muffler on top was probably making one hell of a noise. Leave it, take it off, don't really matter. It's not eating much. But if you do take it off, plug the holes!
It's a ton easier to let them be and cut the belts.