Is this radiator a good deal?

The guy I bought my Dart off of said that it would overheat sometimes because even though it once had a 318 and now is a 360 car it has a /6 radiator in it. I have drove the car over the weekends a few time and I have had no problems with it but the weather has been cool to cold so far but I am afraid I might have issues when it gets hot if I don't change out the radiator. Searching around I found this and was wondering if it might be good enough or if I should just look more something more.

http://www.shepherdautoparts.com/au...dge/dart/w5LDkcOXw5fDm8K7w5PDl8Oaw5rCosKi.htm