With help from my local Chevy parts man we were able to identify the proper part number. The AC Delco part number is 213-112 and the GM part number is 6484242. The GM parts manual calls the piece an "Air Cleaner Thermal Sensor Unit." I searched online and discovered the part is no longer made. Someone on ebay is advertising one for $130+ but that's too expensive for me especially since my sensor looks fine and I assume works well -- I was just attempting to update it.
If anyone locates this sensor and the price is reasonable, I'm interested.