AC Line Routing

[lkt1954]

Working on the AC for my 70 C10 and I have a couple of questions on running ac/heater hose lines.

The firewall has been smoothed and an old air hurricane unit is installed. On this unit all the lines are on the right side and they are about 8-10 inches from the fresh air vent hole. It appears to me the only route I have is through the fresh air vent hole to run the lines.
My question(s) are- is there enough room where I have drawn the circle on the cab go through the firewall there (I can mock up the outer fender and run a tape line, as I would like to keep the line hidden) or can I run them out the bottom of the fresh air box and up the fender? I'm concerned there is not enough room in the front of the fresh air box to go that route ( its hard to gauge what room you have by just feeling that area.
I have both the diamond and vertical template for cutting the holes.
Any thoughts and/or suggestions here? I don't want to screw up a finished firewall.

Thanks