Tach Talk

[Peter Lucas <pllj@earthlink.net>]

A few weeks ago I posted a question regarding putting an electronic tach
in an early model Spitfire. Since then, I got a hold of a tach,
(electronic), out of a late model Spitfire. 

Here's the question: 

1)      Can a negetive earth tach be used in a positive earth car?

2)      How do I wire this with out looping through the ignition-
        (Either in the pos or neg application)?

Thanks in advance,
PL      '64 Spitfire