Hmmm, odd. Still no pics, eh? Is this a mountain bike? Which portion of the frame are we talking about? Top tube, downtube, chainstay?

If it's on a top tube, are there three hoops that hold the housing? If so, they'll sometimes be too small to fit ferules through so you'll need to feed bare cable housing through, then place a ferule on either end of the cable housing after feeding it through the three hoops and cutting it to length. Leave the length too long at first until you get things dialed in and you know you can fully turn your bars and that you have your stem height where you want it, etc.

The more details you can supply the quicker an answer can be zeroed in on.

Zip-tied full housing runs should work if you're using new cables/housing and lube the cables with light oil or Tri Flow.

1981 style friction shifters will be more tolerant of full housing runs than newer indexed systems.

EDIT: actually most deraileurs aren't setup to accept a full housing run, so you'll have to terminate the housing run before it reaches the deraileur somehow. But full housing run for the rear brake, no problemo. Every 1981 bike I've seen had a full housing run for the rear brake.