Engine vibration will crack any known hard line- need some flex. Use a dash-4 Aeroquip stainless flex line for chassis-hardline to-clutch. A dash-4-to-1/8" or -1/4" pipe fitting screws into the stock slave cylinder and the dash-4 on other end of this fitting screws into the flex hose. A double female dash-4 screws into the stock brass Tee fitting under the car and into the other end of the flex hose (use an o-ring on this end for insurance).
Good for 3000 psi, most AN fittings are stainless so weather proof, indestructible and easy to install. You'll have to measure what length hose you need- something like 2 ft or so. Does not need to be exact- leave some slack. Bleed system & you're done forever with this line.