I hadn't seen it done until we saw the good doctors roadracer a while back and I decided I would duplicate this mod. I know turboguzzi has also posted some pics of his external lines too. In my case the main reason for this was to avoid any oil leaks from those o-rings in the top end. I'd like to say first that I have no reason to doubt its effectiveness, but I expect there will be some negative feedback too, so even if it's only for your enjoyment here goes.
I decided to access supply from the right end of the oil gallery, this being the easiest. BUT I'm working on a frame slider type protector here because in a right side crash serious engine case damage is possible with the fittings in there.
The larger single hose is a -5 ending at a hydraulic tee. In either male taper side of the tee I enlarged the orifice and installed (interference fit) a 750 oil restrictor, same ID, smaller OD as the 500 item. The other two lines are equal length -4 hose and when attached keep the restrictors in place. These two lines end with banjo fittings.
There is an aluminum plug pressed in either end of the oil gallery in the cylinder head. The 77 & 78 model years use a larger plug and when removed no drilling was necessary to run the tap. The earlier years will need that hole enlarged first. The next step was to insert a 10x1.25mm helicoil. The banjo bolts I used needed to be shortened slightly so as not to block the oil supply orifice that feeds the cam end.
It is also necessary to block the existing oil passages. In this case I drilled the passage above the main journals, and tapped a 1/4" hole deep enough to bury a setscrew and installed with permanent loctite.
Then in the oil passage north of the head gasket surface did the same thing for a 3/16" setscrew.
That's it in a nutshell. It's really necessary to thoroughly clean any fillings from drilling & tapping. Use a small bottle brush, varsol and lots of compressed air and be sure no burrs remain. Thanks to xtalon for the coaching!