I thought I would follow this up.
Steve H turned me on to
Westach who made me a great 6V 3IMP/rev 3500RPM tach. (Thanks Jerry Hotrod Lincoln for that info)
I installed it in one of Westachs bullet housings.
Here it is
up close, and
with the other gauges. The 2in gauge was $125, bullet housing $16, light kit $6.
It is well worth it to me!
I just noticed the reflection of wires from my
C3P0 phone protector in the face of the tach, if anyone is wondering what it is.