Oil temp sender!

[makeitfit]

Hi guys I'm trying to fit the oil temp sender for my gauges. Can anyone tell me what size thread I need to adapt this alen key blank in the pic.

It's a bit hard to see but it's to the left of the oil pressure sensor in the pic.
It looks like it's about 1/2" ish in old money:nenau

 

[tezzer]

im not 100% sure, but i think the sender needs to be fitted into the sump, that way the sender is sitting in oil,

 

[makeitfit]

I see your point but thought this spot already has a tapping and as it's on the oil filter assy, there must be oil here too
Or she go BANG