Oil temp sensor

Hi there,
Trying to rig up an oil temp sensor. Was advised be Merlin motor sport best place was to fit is in lieu of sump plug, to that end does anybody know the thread size of the sump plug?

Or any other suggestions.

Dave

1/ take the sump plug out and measure it.
2/ Put part no into google for some clues.
3/ Order all sizes and return all unused items.

mine is an early car, and has a temp sensor switch on side of sump.

Haha cheers mate for your words of wisdom.

My 610 still had the side entry for the temperature sender as well as the drain plug, so your GTA should have it too...don't ask how I know...
First oil change wasn't complete as I didn't spot the correct sump plug due to cack on the bottom first so drained it through the side plug...the cack and muck over the drain plug caused by leaking drive shaft pins as it happens....topical that.
Leaking pins were fixed quickly by Paul Sage, common issue when removed.

Cheers Lee,
Will have a look tomorrow.

Dave