Layed out holes on both Channel Doublers (7F7-8C). Drilled pilot holees.Clecoed channel doublers to Vertical Lower Channel (7F7-2C)Drilled holes on channel.Opened the center holes on channel doubler and channel on both sides to 5/8".Cut the vertical lower channel flange to a width of 33mm fro the end of the channel doublers to the bottom of the channel.Layed out pattern and drilled holes on the Vertical Lower Channel (7F7-2C). Clecoed it to the Firewall (7F7).
