I was just looking for pics of tachs in dealership sales brochures. The 72 Challenger brochure printed in August of 71 shows a 70-71 dash with an 8K tach. unfortunately you can't see the redline due to the angle of the picture.

In the Illustrated Facts and Features Manuals (unknown print dates)...
The 71 Challenger manual shows a 70-71 dash with a 7K tach.
The 72 Challenger manual shows a different 70-71 dash with a 7K tach.
The 74 Challenger manuals picture is washed out and hard to see, but I think it's a 7K tach.

Only the 70 challenger and 70 barracuda manuals show 8K tachs, but interestingly they both have a different gauge face than what we're all used to seeing. Instead of the needle sweeping from lower right around to upper right, it sweeps from lower left around to lower right kind of like the speedometer.


All of that info may not mean much, but I think we should still be looking at the late 71/early 72 cars for more clues.

Tav