Re: Fuse box question
Those appear to be OE style connections, so we could use some more info to help. What factory options does the car have, and what does it have that does not work (because you said the red wires are disconnected.
Gray is often used for lighting, and being hooked to the ACC spade, the circuit would be something that only draws power with the key turned. The reds being on the BAT terminal is a circuit getting full time power, like a clock.
I'll have to look at the tach - center fuel gauge option, to see where the separate tach harness plugged into. It would just be helpful to know what's in the car now, to see if you can get something working that currently doesn't, plus get you juice for the tach.
69 'vert project big block/TKO 600 RR
68 'vert driver RS clone -- gone!