Yur right, my mistake. Most of theres is true 1", but you can get them in a 1.25" from them. I thought mine was 1.25", ill have to measure. I used there 26" in an A body and had to fabricate a bit to fit. You want bolt in. I understand. It is a good radiator thou keeping my 511 filled almost to the top cool. I do use a mechanical fan too.