Can I use the block drain for a temp sender?

I'd like to keep the factory gauge but install an aftermarket one that actually indicates the temp.

There is a threaded hole near the pass side oil pan rail that I believe is the block drain.

Can I use this?

It would also help hide the big, shiny spring encased sender lead in my otherwise stock engine bay.

I can't seem to find any info online about what the difference in temp might be between the water in the top of the engine and the bottom.