I have a KR racing manual somewhere, has a KRRR on the cover
extensive gearing info, I think breather info, and I think some head specs or mods. (might be description of relieving tops of cylinders)
I will try to dig it out and see if There is any info in there that will help you. I think there is no photos but a few technical drawings. I think it is from late 60s or 70, end of the KRs
Not sure what you mean by speedway, I am thinking you mean flat track or TT..
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