Ray, I just sold a 8Ktach. I did a little research(very little) I was told the Super Cobra Jets got a 8K tach. the CJs got a 6K. I could be wrong, the info I got was not Ford fact. Any way I now have had 2 351 2vs that had 8K tachs when I got them. My dark green 70 XR7 has one. I do not know if they came from the factory with them Neal.