Help Identifying a Part ... Please!

[firecracker]

I need help figuring out what part this is. This is where my car was leaking coolant/antifreeze from and I hope replacing it solves my overheating problems. The only thing is I have no clue what it was. Was going to go to Advanced Auto but they close early in my town on Saturdays now.
If anyone has any clue as to what this is I would be really thankful. It is attached to the engine block on the drivers side of the car. It is kind of under the power steering fluid container as you can see in the third picture.
Thanks

Joel

http://www.gaownersclub.com/forum/attachment.php?s=&attachmentid=9619

[firecracker]

Ahh ... forgot to add pic.
Please delete this reply.

[firecracker]

Different Angle

[firecracker]

Where it was attached at.

[cheap80Z28]

I'm not for sure, but it looks kinda like where the radiator and heater hoses hook up. It might be the thermastat housing. At least that what it looks like on the 350 engine
steve

[HeyDace]

Actually, its the water outlet housing. The t-stat is located under the water pump.