Drain Plug for FE Oil Pan

[dandascott]

I have a stock 427 S.O. with original high capacity oil pan (with windage tray). Now, I am looking to add an oil temp sending unit in the drain plug. What I am thinking of doing is getting a new drain plug and drilling and tapping for the sending unit to thread into the drain plug. Then when that looks how I want it, I will replace the old drain plug.

Does anyone know what the threads are for this ? The engine is full of oil, so it is a pain to take off and check if someone has a good idea.

Thanks in advance.