What size for trans drain plug for temp gauge?

[bdv]

I am looking to put a drain plug in my 4L80E trans. Having reviewed post talking about putting a temp sensor in plug hole. So the question is what size for the drain plug, I have not yet checked out which temp sensor to use. Was thinking to use 1/2" NPT thread.

Thanks for the help Brent.

[mhagie]

Rule of thumb mechanical gauge = 1/2 npt
electrical gauge = 1/8 npt
merle

[damork]

I used a 1/8 bung from Autometer to weld into my pan for the temp sensor. The pan is the 2WD version which I ordered because it came with a drain plug. I just added the temp sensor so it was separate.

The pan was under $30 from GM and having the two separated was worth it to me.

There's a picture of the pan here the last time I had it out.

http://community.webshots.com/album/42727688JuUMeK