"Jim Burns" writes:

One option is to simply get a mechanical dual tach and connect both tach
cables to the single tach but I don't know of a dual recording tach that has
dual hour meters. Anybody?

I probably have the one we pulled from our Aztec in my junk box.

So far, I have not found a company that makes a dual electronic tach.
Neither E.I or Horizon seem to offer a dual tach.

I was told that Horizon would have a dual tach. "soon" when we were
looking in 2001.

Also, due to panel
configuration, I want a 3 1/8" dia tach not the smaller 2 1/4" tachs that EI
or Horizon offer, I have no room for additional 2 1/4" gauges.

The Horizon P-1000 is a larger tach.

Another option is (always) on the horizon...
http://diamondaire.com/aztec.htm

Rochester engine instrumentation.We are currently working with
Rochester Gauges of Texas to introduce new 2-1/4" dual-needle
STC'd backlit gauges. [...] A 3-1/8" dual electric STC'd
tachometer will also be available.
(They've been saying that for awhile now.)

Is there anybody out there with any insight into this dilemma?

It's worth pursuing. I hate mechanical tachs. I've replaced those
damn cables way too many times. It makes no sense to have all that
crap in the plane just to provide a really lousy estimate of engine
speed. In a single it's o.k. but in a twin it's ridiculous. (I recall
the joy of yanking those cable housings out of my plane!)

You will love an electronic tach. I especially like the mag. failure
lights and the mag. drop feature. Having a tach. that always works and
is accurate without constant maintenance is pretty sweet too.

--kyler