Install airframe to engine ground leads. As I have planned a 2 AWG dedicated ground with a firewall pass through, the 2 AWG leads were routed from the pass through post to the empty magneto mount.
For redundancy, I opted to run two grond leads from the firewall post, one to each magneto mount bolt.
The cables were fabricated using a hydraulic crimper and finished with double wall heat shrink. The cables were then supported mid span with adel clamps.