For grounding the engine (and thus the starter and alternators) I decided to both install the Vans-recommended (OP-37) grounding straps, and one to the firewall grounding block - that gives me redundancy (it's still an electrically-dependent airplane), and has little chance of creating a ground loop. I drilled up the engine mount tabs for AN5 bolts (did I mention drilling hard steel in a hard-to-reach spot is a pain?), removed the powder coat from approximately the contact area of the ground strap terminal, and attached them:
Engine mount hole for grounding
Engine mount hole for grounding, with powder coat removed
Grounding strap between engine and engine mount
Grounding strap between engine and engine mount
Grounding strap between engine and firewall
We also used ProSeal to seal all the antennas - this made a bigger mess than expected and required quite a bit of cleanup to get a smooth fillet (a hint we didn't see or think of in time was to apply masking tape to the antennas to make a clean edge):
Sealed COM, Stormscope and ELT antennas
Sealed GPS antennas
Sealed TAS antenna
Sealed transponder antenna
Sealed GPS antenna before cleanup
Sealed GPS antenna after cleanup
We installed several more ClickBond fasteners, for the forward and tailcone servo wires, the top forward conduit wires (away from the screws that attach the cabin cover), and the remaining overhead console fasteners:
Heat tee servo wires secured to tunnel wall
Tailcone vent servo wires secured to the ceiling
After installing the fuel pump, we ran the remaining wires through the forward tunnel, connecting the GHA15 and the stick grip connectors on both sides:
Tunnel wiring secured around the fuel pump
Stick grip connectors secure in place in the tunnel
Stick grip connector coming out of the tunnel
There's not a lot left to do with avionics (well, at least compared to how much we've done so far) - once the tunnel is fully closed up, the alternator regulators are connected, and I update the firmware on the O2 sensor controller, the main things left will be securing the firewall-forward wiring, installing the overhead console inserts, and actually installing the panel and avionics permanently in place.
