radiator

Sounds like you are using straight water in your cooling system. A good flush and fill with a high quality 50/50 anti-freeze every three years would have prevented that.

As for a radiator replacement, get the dimensions, tube count, inlet and outlet sizes and locations, and mounting configuration and go to an auto parts store or NAPA.

Also, a coolant filter would have helped prevent this.

Unless the radiator is completely shot.  Why not take it to a radiator shop and have it recored???????