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

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.