Temperature sender

Hi
Just put re skimmed cylinder head back on after cooking engine,
I want to put an additional temperature gauge in the car, I thought about putting an adaptor on the top hose,
Does anyone know the diameter for the top hose, there are some on flea bay but not sure which diameter to get.
Thanks

You're probably better off drilling the outlet elbow from the head into the top hose for an extra sender. That way you can keep a standard top hose.
It's a relatively common mod to add an additional & more accurate temperature gauge.

why not use the correct thermostat housing elbow with the sensor already in - you can also fit an overheat sender in it. - err3738



The two switches are PRC3366 & PRC3541
and second is PRC3541.

Made the rash assumption that you had a td5 D2 - lol.
What engine have you got?