I don't have a coolant overflow tank, my car didn't come with one (late '69 350/350). So when it gets hot, water comes out of the overflow onto the street. When it cools down, it just sucks in air. That means that most of the time, I'm only using the bottom 3/4ths of my radiator.

So I am considering installing one. But I notice that where it is usually installed, I have a long A/C unit (old axial style) blocking that area. Newer A/Cs (radial style) are much shorter, so there is room for an overflow.

So I could replace the A/C with a newer shorter one, and then install the coolant overflow behind it.

But I'm actually leaning towards scrapping the A/C altogether. I never use it (actually the console controls are messed up, and I'm not ready to tackle that yet). Even if the console was working, I wouldn't use it. It's mid-summer here in NZ, and yet the air is always cooled by the ocean, or the high altitudes of the mountains. This is far from Arizona. Rolling down the windows is perfect. Taking the tops off is heaven. Besides that, the A/C is blocking access to plugs #2 and #4, so it's been on my ****list for a while now.

Before I make any decisions, I'd really like to get some opinions. How hard is it to remove the A/C?

 

On my 77 model the overflow tank is tucked up under the pass fender right in front of the heater blower motor. You might try one of these. All the vette parts houses have them.