Leak Test

The result? the coupling held 115+ psig for better than a week with absolutely no leakdown. I'd say that's a successful test. Sure, vibration could be an issue...but that would be an issue for any threaded connection on the car...

For reference there are supports, internal to the tunnel, that are used to hold the fuel line in place. If you look closely at the previous post, you can see the front most support which also holds the clutch cable tube and a tube for the heater flap cables. I threaded my new tube thru that.

At the rear, at the point where the tunnel splits to create the transmission mounting yoke, there is a support as well. That support also holds the driver's side brake lines IIRC. It was nearly impossible for me to thread my tube back through that support. So I lashed the support to the brake line using a cable tie. The tube seems inherently much more secure than did the original tube.