When replacing the oil pressure tube from the rear of the V8 engine through the firewall to the rear of the guage on the cluster is there a proper way to do it?

What I mean is that it is full of air so do I need to have it loose on the guage side and start the engine and let the air bleed out and get oil up there by the guage?

Or does the quage work off the air getting pressurized by the oil that is pressurized by the oil as the engine runs and forces some oil up the line?

Also the new line I got from Classic Parts seems to hae a smaller hole in the line. It does not blow as easily as the old one. Is that OK? Does it just need a path to the guage but the size does not matter?