Cajun Tach Shop Upgrade
 

I bought the pictured Tach Board off EBay from the Cajun Tach Shop Store and a friend installed in my factory original tach. My tach was always reading 7-800 RPM high at highway speeds. With this new board its very accurate now. Just passing along in case someone having the same issues. I have the Petronix Stock look Distributor and components on the truck.

Re: Cajun Tach Shop Upgrade
 

I can also recommend Greg @ https://www.cajuntachshop.com/

My OE tach finally gave up so I replaced it with an after market tach.
The replacement tachometer only lasted a couple of years.
I sent both to Greg for the upgrades he had been working on and he successfully repaired both.

Re: Cajun Tach Shop Upgrade
 

Pertronix Ignitor I and II are OK with any Tach. Ignitor III is an electronic multi spark unit like MSD. A friend with a '72 F-250 and 429 BBF had the mark III, and his tach went crazy. He called Pertronix, and they told him to retrofit to a mark II if he wanted to run a Tach.