If all the sensors and wiring are on the block, you establish a common ground point at the block. Running supplemental wires back to the battery doesn't make sense.Very interesting Jim. The MegaSquirt people insist that everything go to the MegaSquirt, then grounded to the block. Rootes Racer insisted that everything terminate at the battery, the wheel goes 'round and 'round.
If there's some documentation on this beast on line someplace?