adding a tach to my non tach 68

[Ieatcamaros]

Most people will tell you that one is no better than the other. Some people (like me) had just rather have a mechanical gauge. Lets use the oil pressure gauge as an example. A mechanical op gauge uses a nylon or copper line running from the block to the back of the gauge. You will have an oil line inside your car. To many people this is not cool. But aside from getting the correct fittings to fit the line to the block, that is all a mechanical gauge consists of. An electrical gauge uses a sending unit that you mount on the block and run a wire from the sending unit to the back of the gauge. There is more that could fail in an electrical gauge. The sending unit and the gauge itself. With a mechanical gauge, the gauge itself is the only thing you have to worry about. I like mechanical gauges better because I have a hard time trusting a sending unit. Just think about factory gauges.

Are you going to put in a fuel pressure gauge or a fuel level gauge? If it's a fuel pressure gauge, I'd hook it up and leave it under the hood somewhere. Then you can put the voltmeter in that hole. If it's a fuel level gauge and you are going to get a pod, then some gauge suggestions to fill the other hole are: Trans temp (if you have an auto), Oil temp, or an air/fuel ratio gauge.