The oil that lubricates the rocker arms comes from the driver's side of the engine, from a roughly triangular-shaped sheet metal cover near the oil pan rail called an "oil distributor". There is a copper line that goes diagonally through the water jacket that ends up under the pushrod cover. Don't try to remove that tube- - - -it's a one-time installation with special compression fittings, and the line must be replaced if it's disturbed. Some of the resto-ripoff places have a kit with the copper tubing and all the fittings that are needed to replace it. If the line through the water jacket is intact it's OK to splice it under the side cover- - -just be careful not to let the line rub on the pushrods.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!