How does the Rallye Dash Tach hookup?

OK, im working on the 71 Demon340 (like in my avatar pic), its a new wire harness from M&H, the blury pic is an old fuseblock I took a picture of for my reference. I am a picture guy and when it comes to electrical, like many on this forum, I couldn't tell you if, or where anything has power or will ever get power. Quite frankly, it's embarassing for a guy my age to not understand simple electronics. There, I owe you $100/hr. I was kinda hoping you would say, "no you idiot, plug it to that blade!" .....yes?