Radiator drain plug HELP!!!

[wldcat10]

Took my ‘70 out today around to the gas station to fill her up and air up tires. As I waited for air compressor to be freed up, I got out and popped the hood to look for any leaks and boom! My drain plug blows out. I went to autozone around corner to grab a drain plug, they give me a 1/8 plug, too small. I go return it and the 3/8 is a special order item. So I grab a 1/4 drain plug and it’s too big! I looked up the size/specs and shows that 1/4 drain plug should be the one. Am I missing something? Any input is appreciated....

[Sheepdip]

I'd have a hunch that there are lot's of radiator shops in Arizona. I would try them for a correct fit.

[Steeveedee]

Is the plug you got straight pipe or tapered pipe? Maybe they sold you a straight pipe version?

[El Dorado Jim]

it should be a 1/4"NPT pipe plug,(National pipe threads) it is physically bigger than 1/4 " and has tapered threads,It should be brass, I usually install a 1/4 " petcock in there so you can just loosen a knob and drain the radiator that way, it gives you control ,https://shop.advanceautoparts.com/p/...1106/5701643-P