What Is This

When I bought my 87 gt the guy who sold it to me also gave me an x-pipe. I was ready to put it on but this one part does not look right. It is welded to one of the pipes and the tube is open. Does something hook up to it or is it something the guy did to bypass something. I have no idea what it is and need a little help. Is it okay to put on? PLease let me know
Thanks
I will post pictures in a minute
The pictures are too big to upload, but does anyone have any idea what I am talking about?

haha, It looks like it was home made, when you get an off road x-pipe do you have to place it yourself because it looks like it was done in a driveway, it doesnt look like it came from a factory