Imo, stick with the original routing. I ran one across the engine cross member. While it did clean up the firewall, it proved problematic when removing the oil pan and crank.

If you don't like the looks of the contrast between the line and black firewall, paint the line. Hidden lines and wiring may look cool, but I've found they're a pita to access and work on.

My  new Shelby GT350 had the RF brake lines running across the front of the frame, taking the long way to get there. On my 66, they runin the stock location across the firewall. 

Bottom line:   Put them where you want them. Just make sure it is a location where they won’t get damaged by road debris.  Like that truck tire I could not avoid at 70 mph on the way back from the Michigan bash.

The important thing is that the end of the hard line is secured where it cannot move, and the more important thing is that the flexible lines cannot get hung up on anything or rub on anything or get kinked through full left-right and up-down movement of steering or suspension. I have seen some pretty scary brake lines on some Mustangs in my day.

I have my flex lines attached in front of wheel center line.
That’s where I had relocated frame mount with Granada brakes.
I had taken measurements on a Granada to locate in same position.
I figured Ford had spent the time and money already.
25 years ago using stock replacement parts was really the only affordable option.

I had thought about the crossmember route.
Especially the oil pan...how often does that need to come off?
Hopefully never.

Thanks guys for other options.

Nos681 wrote:

I had thought about the crossmember route.
Especially the oil pan...how often does that need to come off?
Hopefully never.

In theory and reality are incongruous. I too didn't think I'd be removing the oil pan many times due to failed rear seals and the number 3 crank thrust bearing. Murphy's #1 Law is spot on.