Where to plumb in the water temp gauge

[grinder]

Hiya chaps

just bought a water temp gauge off ebay ( couldnt resist at £2.20 !! )

right then - where the hell does the thing go

i have a 1990 TII and been having a nosey round the engine bay

and have no idea if there is a spare place to bolt it into ??

someone has said i have 2 choices

1 - somewhere near the oil pressure sender ( too much crap in the way to actually see it though )
2 - behind the water pump ( again cant see it though )

do any of these places actually exist on the TII ( was shown on a 12a engine )

and out of interest - where does the stock gauge get its reading from ??

or am i best just getting a pipe that fits into the top hose and take a reading  from there

and whilst you are all reading this ... how can i tell what the thread size is on the water temp gauge sender unit - from reading up about them - they only come in about 4 thread sizes - so how can i tell what mine is ??

Thanks

Stu

[t2rew]

the stock sender is just below the oil pressure sender and it really is only just visable put your hand down there and youll be able to feel it.  not sure on the size. i would say its metric.

[grinder]

yeah i thought it was - thats where it is on the spare engine - and thats why the haynes manual said

so im a best with the top hose idea then ??

ta

stu