I did run a separate ground for instrumentation, separate from the #1 AWG engine block ground. The #1 AWG pos/neg goes to the starter and engine block. Another #8AWG goes directly from the battery to the dashboard. All of the grounds are distributed from the dash fuse block. I ran a #10 to the rear to the terminal block to breakout grounds. For instrumentation on the engine, the #1AWG serves as the ground as my sensors are all single-wire. They rely on the engine block for the ground path. The alternator is grounded to the engine block as well, on the same bolt that the #1AWG ground comes in. Hope that helps!