[tvgreen]

Has anyone out there found a company offering an original style 5500 RPM tach for a 67 Camaro that is compatible with an HEI distributor?

[JimM]

ok, guess I'll chime in on this.

I had this problem a few years ago, and found a "gizmo" to fix it. Basically it was an adjustable trim capacitor. You install it between the distributor and the tach, and adjust it till the tach needle stops bouncing all over. I don't remember where I got it, believe it was sold as an accessory by one of the aftermarket guage manufacturers. it worked.

[paulm]

Some tachs work some don't. I had trouble with mine, but others have been able to use HEI's and original or aftermarket tachs with no problem.

The solution for me was to build a tach filter (suggested by JohnZ, Thanks John!! [img]graemlins/thumbsup.gif[/img] ). If you search in the electrical section you will find info on it. My tach works great now!

[tvgreen]

Thanks guys, I have some researching and reading to do ahead of me.

[HOTRODSRJ]

I interestingly found that HEI modules are NOT all the same and can cause problems. I had a new Echlin replacement module in my HEI and my tach bounced all over the place...especially at lower rpms. I lived with this for four years and ignored it because after 2500rpms or so it went away.

I switched to a Accel HEI module and coil the bouncing went away and is completely compatible with my tach. Smooth as silk......so the moral to the story is the tach output varies from chip to chip. I would try to swap out the module.