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

Rapid Robert said
it is a 3/8 copper tube from the pass oiling gallery over to the drivers side oiling gallery then the passenger side front oil gallery feed down to the #1 main is blocked & the #1 main is fed from the drivers side gallery. this slow down the passenger side flow past 2,3,4 90 deg turns to the main bearings so they get fed better. several people much smarter than me swear by this mod.

Ok. They are wrong. It was done if you block off the oil at the number 1 main.

Slowing the oil down isn’t true. It just shows they don’t understand basic hydraulics.

You can do it, just don’t expect it to make the oiling system better other than the fact you aren’t pulling any oil off the number 1 main. Which only feeds one rod bearing anyway.