hard or soft copper line for a valley oil gallery bypass line?

The reason is to reverse feed number one main. The tube is only one part of the modification. It is just a better distribution of the supply oil.

Reverse feed the number one main? Go look at a schematic and tell me how that works. The number one main is fed from the front hole of the drivers side gallery.

Just retarded nonsense. No one EVER blocks oil to the number one main BEFORE the main bearing. No one. And if they did, WTF did they gain?