I just converted my 70 from a SB to a BB, so I went out and measured the SB radiator. It was 28 1/4" W X 18 1/2" H not including the tanks. I had a radiator shop build a 4 core for me which is 29" W X 18" H. It bolted right up using the top cover. I did have to purchase the BB shroud however.
I agree with Pat, any reputable rad shop should be able to make one for you.
Hope this helps.
the only thing you can do is have a shop custome make a 3 core (largest that your tanks will hold) out of your old 2 core radiator don't listen to the places that say they can order you a "high efficiency" 2 core because i had one in this 70 model with a 307 and when i put guages on it i found out it was running near 230 deg. after i had a shop make this one it runs 180 now. the small 20 3/4 inch radiator you have is anoying but will work with a 3 core inset and your old tanks. hope this helps concidering i just did it last saturday. jk
sorry but i didn't let you know that you do have a factory size radiator, it's not butchered (i thought that of mine too untill i called the person i bought it from, original owner) and you can't go 4 core like everyone says unless you make mods to the car or jimmy rig it. the 3 core i now have works great and i live in Texas where it is near 100 deg. now so if it works that good here with the air on in the city then it will work for you.
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