Positioned and marked holes for mounting 2nd 1" wire passage hole through the firewall.
Step bit was dull and did not cut clean, but rounded in the hole. Had to use a Dremel with a grinder and/or a cuttoff wheel to finish the hole to allow the pass-thru flange to mount properly.
Once hole was properly prepared, flange was mounted. Applied fireproof compound to the flange where it made contact with the firewall. Installed the flange and then installed all four bolts with nyloc nuts. Had wife hole the wrench on cabin side, while I tightened the nuts on the firewall side.
Installed and clamped the outer fireproof sleeve piece over outer sleeve of the pass-thru tube coming off the flange.
Initial opening for 2nd fireproofed wire passage through the firewall.
1 inch round wire passage flange bolted in place.
Fireproof sleeve installed over 2nd 1" wire passage flange.
