Radiator choices 26" or 22"

I have a complete parts car 73 duster that is a factory /6 a.c car. Would it be likely to have the 26" radiator core support? I would go out and measure it, but it is sitting in a canvas carport at my dads place. We are planning on bringing it over to our lot soon. But I was curious as to if it should be or not. Or at least is likely to be a bigger unit because of it just being an a.c car factory.