Radiator Mounting

Had to replace the radiator due to a small leak. However one of the nuts on the side is completely destroyed. The FSM lists it as P/N 3420 1348, but chryslerpartsdirect says its not a valid P/N. Any ideas?

Posting the year, engine, etc is usually helpful.

I show that part number as the well nut for the side of the 4-cyl radiator? Take the good one down to the parts store and have them match it up. It might be metric, but you can probably swap both the nut and bolt to SAE if you needed to.