[Afterhours]

An electric vacuum gauge? I didn't know they made one........the only one's I've ever seen were mechanical...Hmmm. Either way, they're fairly easy to hook up.
You can easily "t" into an existing vacuum line, but just make sure it's manifold pressure (after the throttle body) or you'll get all kinds of wierd readings.

 

[Afterhours]

I don't think running a small vacuum hose through the firewall is such a big deal. You should be able to route the hose through one of the existing grommets in the firewall.

As for mechanical vs. electric gauge.......if it's anything like I've noticed with oil pressure gauges.....the mechanical ones seem to have a better response. I'm not sure if there's any difference with the vacuum gauges because I've never seen an electrical one before.

You should just hook it up. If you don't like it, you can always change it to a mechanical one later...........then post the electrical one on "For Sale" :biggrin: