High pressure oil feed line diameter

[Dave]

You can make it out of whatever size/diameter you want. The pressure is still going to be coming from the block, the only detailed part you need to get right is the restrictor going into the blower to ensure no popping of seal, and maintaining enough oil pressure to the rest of the block. They're normally about 2mm but the rest of the line can just be made up it wont affect anything as long as restrictor is correct.