My 302 has a stock radiator with a small, round overflow installed by the P.O. When the engine was cold, I took therad cap off to check the coolant. It was about an inch below the neck, but still covered thefins. The overflow has a knurled top, but I didn't try totake itoff. Does the coolant expand when it's hot, then forcing the coolant into the overflow?? And then as it cools, it draws it back into the radiator?Should the overflow be empty when it's cold??

Thanks

 

Yes and yes. Check to see if the hose/tube from the radiator go in the overflow at the bottom and are not cracked, otherwise when your engine cools, it won't draw coolant back into the radiator.
Jim

 

I don't think the resivoir should be completely empty when it is cold, although I am kind of new to the older carbed engines...but the rest of your assumptions are correct.