Overheating issues on a 383 Polara

Wow it's amazing how anytime I search a mopar issue it brings me to this great site that I'm a member of. This car seems to be having the same issue I'm having. I bought a 65 polara for dirt cheap. Runs great, drives great. After about 30 minutes of driving it gets hot, doesn't over heat though. I drove it a lot during the winter and had no problems