This my have been posted before,

[Polygon]

Here is a cool way to figure out RPMs and tire/axle ratios

http://vexer.com/68rt/speed.html

[SeattleCharger]

That is really cool, haven't seen one of those either, thanks

[69_500]

If I'm not mistaken that was created by a board member on here. I remember a thread where he was asking for clear pictures of the tach from a 68-70 Charger.

[Just 6T9 CHGR]

Yep its a board member (0X01B8)

He let me use it on my tech page on my registry site....

http://www.1969chargerregistry.com/tech.html