Strange Throttle Body Plenum On 99 Gt

I have a strange looking throttle body plenum on my 99 GT; it has an extra vacuum pipe on the front of it. I believe it is from a Lincoln, from the Google searching I did. I would like to get this back to original, unless the Lincoln part is desirable for this engine. The casting number is F6AE-9A589-BD. So if anyone has any information about the differences in these parts, I would like to be enlightened.

Also, if someone has replaced their stock throttle body plenum with an after market part, and would like to get rid of the stocker, please let me know.

Thanks in advance!

nashville_bill