Can anyone explain to me why the airbox that came in my '93 is so different from the one I took out of an '87? In the first two photos, my '93 airbox is on the left, the final photo is a close up.

I suspect that some sort of sensor was once attached to the '93 airbox, or perhaps in some markets an airbox temp sensor was used. I don't know, need your thoughts.

Notice these differences:
-The 93 airbox has a hole/tube on the top of the airbox that must be capped off to keep underhood air from entering the airbox; the '87 airbox has the tube, but no hole, thus, no cap.

-The '93 airbox has a section on top that looks like it mates with a sensor of some sort - the two holes on either side are tapped metal, obviously to accomodate screws; the '87 airbox has an odd circular mold, but seems to do nothing.

-The '93 airbox (inside) has a raised section terminating in a point about halfway down - it looks like it may hide a wire/sensor molded into the plastic; the '87 airbox has a dimple, but no raised section that could hide a wire.


Thoughts?