Tomorrow I'll be wiring a new set of SPI gauges into a '91 NA.
I already have an oil filter pedestal adaptor to house the oil temp/pressure sensors, now all I need is a place to put the H2O sensor.
It would be very convenient if I could just use the stock water temp unit and I don't think it would hurt the gauge but here's the question...

Can I piggyback both temp gauges (stock AND SPI) on the same sensor or will that result in screwy readings?
I'd like to keep the original cluster gauge functional (gauge works fine now and is directly in line of sight) and use the full sweep SPI as a sort of calibrator for the stock gauge...if that makes sense.

If the stock sensor won't work, where is the preferred location for an aftermarket unit?
It'd be nice if it didn't require drilling/tapping although I'm redoing the entire coolant system next month (budget permitting) and could do the machine work then if necessary.

Any thoughts appreciated.

 

No.

Check the FAQ for locations to install your aftermarket sensor.