Mechanical oil pressure gauge 1965 Dart GT

65ChargerDart said
The walls of copper weakens when flexed and leaks in short time. I owned and worked on Triumph TR6s for 40 years and they came from the factory with nylon oil pressure lines. Never knew of one to fail, unless improperly seated at the block or gauge.
I run a nylon line on my '65 Dart Charger and recommend you stay with one also.

I used the copper in one of my Sweptline D100's ( way more wiggle room),but I coiled the line at the block ( like a brake line).Never had a leak problem. The way I routed this one to miss all the under dash ac stuff and the ability to drop the ashtray, yes probably better off with the nylon line.