Oil, trans or coolant temp?
For coolant then heater hose would probably be the best bet.
Look here: Accessories - Adapters, Fitting & Hose
You will see the adapters at the top but then scroll down to row 7 and you will see the heater hose bungs, you cut the hose nearest the thermostat housing and insert it there, then install the 3rd part temp sender for the 3rd party gauge.
You may need one of the adapters at the top of the page.
Some senders need to be grounded, the bung should have a ground screw, smaller threaded hole, so use a jumper wire from there to engine bolt or ??, a good ground.
The ones pictured in above link come with the grounding stuff.