I had some trouble bolting the Dynon ammeter shunt to the firewall. I used AN4 bolts since that was the size of the pre-drilled mounting holes but I tightened the lower hole too much and cracked the plastic base. Dynon sells these for $15 so I'll probably purchase a new one even though this is probably fine as is.
I also fabricated two copper strips and bolted them between the top of the shunt and the battery side (unswitched side) of the starter contactor. Copper is very soft so it makes it difficult to drill and work with, at least compared to aluminum.
