Probably the least important aftermarket gauge, but the most challenging to install; Oil Temp!
The only accessible place that i could find was the oil line from the block to the turbo.
As the oil temp probe must be situated in the middle of oil flow - for accurate readings. (in-line)
*please note, all my gauges and therefore the following directions are all based on AutoMeter Sport-Comp II gauges.
You need to make, as they don't exist, a M12x1.25 double bayonet bolt and 1/8th branch fitting.
Now the fun part - i could only find these bolts (not set-screws, as you need a shank for outfeeds) in 304S/S or hi-tensile.
So this makes machining fun as these materials are very hard.
Mic specs off factory bolt and replicate with new bolt. I got the M12 'bayonet' fitting from Pirtek, then just machined a 1/8th female coupling with a nice flat face and TIG welded it to the bayonet fitting. Apparently, these bayonet fittings are only available in crimp/braise/weld - and due the the length of the temp probe, i could not tap the bayonet 1/8th - you will require some stem depth for the probe to locate in.
*NOTE: do not use pipe (PTFE) tape, as this acts as an insulator between the probe and the fittings/block as that's your NEGITIVE return for the probe.
**as per 2 pics.
This then, with some new M12 copper washes replaces the factory bayonet bolt (single).
This is a 'challenging' install, but made easier if you remove the dump pipe.
Also, try to use some silicon flex 1.5mm wire or sleeve your cable with heat shrink to protect it from radiated heat from turbo/dump pipe.