[mitchntx]

Glenn has done tons of research on this and we are both about to the point of have custom machining done.

Autometer guages have a sending unit that is 1/8" NPT.
An LS1 motor has ports machined in, but are 12x1.5 metric.

Sure there are adaptors, but the wall is so thin the adaptors twist off with MINIMAL torque. And by that, not enough to crush a seal enough to prevent a leak.

Why don't they make a 12x1.5 sender?????

The stock sender ohms out WAY different ... almost 1K ohms lower than the AM.

[rmackintosh]

how does that solve the problem of putting NPT parts in METRIC holes that are very close in size?

....OK.....one "word"....

LT1

(IMG:http://www.frrax.com/rrforum/style_emoticons/default/laugh.gif)

....but seriously, it sounds as if the DO make an adaptor, but it is weak in your experience....How tight are you tightening the thing????? Are you using any sealers, teflon tape, etc?

I can't imaging tightening things so tight the fitting would break.... (IMG:http://www.frrax.com/rrforum/style_emoticons/default/unsure.gif) .....my first Autometer guages were plastic tubing and cheap little compression fittings.....never leaked....just melted the tubing in the Datsun! (IMG:http://www.frrax.com/rrforum/style_emoticons/default/biggrin.gif)