EGR on stock 67 289?

It's not EGR, but PVC: Positive Crankcase Ventilation.

Fresh air enters the engine through the (underside of) the oil filler cap and is sucked out into the engine through the hose you described. It's purpose is to ventilate the gas that leaks past the piston rings during compression. The flow is small and shouldn't affect engine performance much.

It's essential that the engine has some sort of ventilation. I'd recommend keeping the current system. Those gases the engine vents out are not too healthy and may creep into the interior. It's smells and gives you a headache. So, for a street driven car, it's best that engine "re-consumes" them.

Race cars usually just have breathers on the valve cover, but racing drivers are tough guys who don't care about headaches

Correct, it also relieves pressure in the crankcase which is ggod for your engine. BTW, it is PCV (positive crankcase ventilation), not PVC (poly vinyl chloride). PVC is the plastic pipe for plumbing your house.

Sorry, it's of course called, PCV, not PVC.

Switching the valve covers may work, but that puts your oil cap in the opposite corner of the engine. Don't know if that's a convenient place.