Are you working with a spray-oiler 216 or an early 235, or is it an early full pressure 235? The 216 and pre-54 spray oiler 235s with the triangular shaped sheet metal oil distributor near the oil pan rail have a copper {not steel) tube that passes through the water jacket and ends up at the rocker arm shaft. Early full pressure 235s have a steel tube under the pushrod cover that gets pressurized oil from the rear cam bearing boss. Both types are subject to wear from contact with the pushrods and/or breakage due to vibration. DO NOT try to replace the line through the water jacket with steel- - - - -it will rust out. The copper tube is soldered to the adapter fittings on both sides of the water jacket, and must be destroyed to remove it- - - -it's a one time installation. Some of the resto-ripoff places sell a kit with tubing and the fittings needed for that project.
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!