Noob question; Installing intellitronix digital gauge, (tw: LOTS OF DUMB QUESTIONS)

Ok so I am being told that I need to ground the water sender, and the dash to the engine block.

I have no clue why the engine block. Based on my research MOPAR 318s have a bolt hole near the head to ground TO the engine block. Problem is, mine has a wire connected to the negative side of the battery and it also connects to the chassis.

Would that mean I can loosen that bolt and ground my dash to that same bolt/bolt hole?

Pic 2 is where I "grounded" my dash at the fuel sender housing as per the instructions. The grounding clip thing is pretty rusted out and worn out so I just cleaned up that spot you see encircled and wrapped a solid 18 gauge wire and secured it with tape.

That good? Or did I mess up?

IMG-3463.jpg

IMG-3459.jpg