Part cracked

Hi, I drive a 1992 Cutlass Supreme, 2 door, 3.1 L. A part under the hood cracked and Im not exactly sure what it is. Im pretty sure it has to do with antifreeze because when I popped the hood I saw green stuff on the air filter. The car overheated also. Sense I don't know what the part is called. I took some picture of it.
http://files.myopera.com/schmitty8225/files/Car%20001.jpg
http://files.myopera.com/schmitty8225/files/Car%20002.jpg
http://files.myopera.com/schmitty8225/files/Car%200034.jpg
The part that is blue is the location of the part.
Thanks for the help.

Welcome to AF. Looks like the radiator neck, you will need another rad. also in the pics your upper dog bone engine mounts are bad.

Welcome to AF. Looks like the radiator neck, you will need another rad. also in the pics your upper dog bone engine mounts are bad.Thanks. I assume the mount is the thing that looks like the dog bone, hense the name. How much do you think these 2 things will run me?