318 Running Really Hot

Well you need to figure out what the temperature actually IS. A factory gauge won't tell you that. Did it stop puking out the overflow? Does your guts tell you it cooled down?

What was the previous ratio of coolant? Frankly, I doubt you have fixed anything.

OVERfilling a rad will not cause overheating, but it WILL cause puking out the overflow until things get normalized.

Last, what is the ambient temperature there? Humidity? "Hot and dry" = poor cooling