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68 Factory Tach and Pertronix

How low? My petronix lowered my tach by about 150 rpms...barely noticeable.
 
That is about the same. Since I have not had the engine above idle. I did not know if that was a proportional drop of just a constant drop of around 200 rpms.
 
I can't tell you for sure as I have no way of independently measuring rpms at speed. I had my rally pac refurbished by Tachman, and I drove Midlife up to GA to pick it up and install it. I noticed the RPM drop, and asked him directly about it. He claimed when he had it on his machine, it was perfect. You can adjust the tach needle with the set-screw at the very bottom (at least on the rally pack for 65/66's).
 
Thanks Randy.

Tachman also refurbished my tach. Hopefully it will be just a few hundred off all the way.

Holler at me next time you are in town.
 
my 67 tach is off too with the MSD/electronic ignition. I don't think the 67/68 have an adjustment, at least not that I could find.
 
So that explains why mine is reading a few hundred low. According to the various online rpm calculators I should be running about 2050 rpm at 70 mph, and it was reading about 1800 or so.

Frank
 
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