[blucar]

Lets re-phrase the question of copper fuel/hydraulic lines vs steel lines..
If copper was better for automotive use, the factory would specify and/or use it. It only takes one broken fuel line to totally ruin an afternoon and/or vehicle.
If you don't have the means to make new steel lines, have someone make one for you.
A good example of how the lines should be ran is to look at a modern vehicle, the fuel lines will be located away from the block, with a short rubber/braided hose between the chassis lines and the engine.