Shiin

I had the same problem with my 72' 240Z and one way I solved it was a new water pump and fan clutch. You may also have a intake manifold thermostat, if you do u should check that also. There are other reasons that it over heat, but other than that it sounds really good, just look for any rush spot because that where it will cost a lot to fix. It's well worth the time and effort if you plan to restore it, like I plan to do. Good Luck