63 Dart overheating issue

Mineallmine said
Don't have a vacuum guage so i can't tell you exact measurements. Also again I checked mechanical advance with the vacuum disconnected and as you increase the RPMs the timing changes as well so I'm confident that is all correct as well

You need to get a vacume gauge.

And it is important to know what these old cars are doing.

I think you are on the right track that your rad is clogged.

But too little advance will cause heat issues too.