Interesting, I never knew there was a difference. So I guess that means the 69' 351w distributor was one-of-a-kind since that was the first year of production?The reason is the distributor body. The distributor body was changed to a taller one in 1970, and will clear the manifold. Early ones hit. You can simply buy a used 70+ distributor (even Duraspark electronic types - but not TFI), and swap the guts to keep your timing curve original, or go aftermarket and re-curve it to run right. Or change the manifold.