My Vista was having a misfire I couldn't fix, turns out the distributor was worn out (excessive vertical and horizontal.play)
The previous owner converted it to a Pertronix system. Upon inspection I noticed the disc with the magnets / sensors was warped and one magnet was loose.
I decided to purchased a DUI HEI setup and it made a big difference in idle / drivability.
The Tach wire was not hooked up previously, so I put it in the Tach terminal on HEi. It works but not accurate. Is there a different procedure for an HEI or is the Tach just worn?

 

The tach terminal on an HEI outputs a square wave to the tachometer. This is identical to the signal from points ignition. So, no different procedure for HEI.

The factory tachometers were not accurate when they were new, so probably not much difference there either.

To get the best accuracy, install an aftermarket tach. If you only want your current tach to read more realistically, you could take it or send it to an instrument shop to have the internals changed to a modern circuit.

I did that with mine and was very pleased with the result. I have a digital ignition cutoff at 6000 rpm--at that point my reworked original tach reads just a bit over 6000 rpm.

 

If you could refer a place that repairs / upgrades the Tach I would appreciate it.
On another note the clock doesn't work either, is that repairable?

 

The place that did my instrument work is now closed. Let's wait for another poster to recommend a good instrument repair shop.

The same place will be able to repair your clock as well.

If no one replies in a few days, start another thread specifically asking for recommendation on an instrument repair shop.

Gary

 

I use Redline Guage and Clock Repair in Michigan for my repairs. I live a couple of hours from John’s shop so I delivery whatever I have that needs repaired. He is very personable and does excellent, fast work. While not cheap, your parts will look new.

 

I second Redline Gauge and Clock Repair. My tach and gauge pods came back acting and looking like they were just pulled from the box. Both work great. Not inexpensive, but worth it in my book.