gauges - mechanical or electric?

[pitts12driver]

Ok - very naive question...

I'm about ready to wire up my 1969 Camaro. I'm not using anything from the original interior. I'm powering the car with a new LS3, and a Keisler T56 package.

I know the T56 has outputs for both electric and mechanical speedometer, but I'm trying to figure out if it really matters which I use. I'm also curious about the most appropriate temperature and pressure ranges for water temp, oil pressure, etc.

All advice welcomed. I'm deciding between Auto Meter, Classic, or NuVintage gauges. While I've heard some issues about inaccuracy with Auto Meter, I'm leaning towards them simply because of the 5" tach/speedo options.

thanks in advance - Adam