Classic Auto Air in 67 Barracuda Factory Non AC

With regard to the cover plate that seals the tubes through the firewall, I didn't drill any holes into the firewall to secure that plate.

Instead I installed threaded rivets into the existing holes in the firewall then drilled holes in the plastic cover to match the location of the threaded rivets and used factory style bolts with washers to secure the plastic plate.

I also sealed the tubes through the plastic plate with dum-dum flexible sealant for the factory look.

I can post pictures later today when I get home.