The Stovebolt Site Forums The Shop Area Engine Shop Oil line to rocker assembly missing

I have a similar situation with a later 261. The block was cast in 1962 and no serial number indicating it was a replacement block, but had a 1957 261 head on it. When I got it, it had an external oil supply line feeding off a T-fitting on the oil pressure gauge port that wrapped around the exterior rear of the engine and back up the passenger side and then feed into a central oil port in the side of the head just below the valve cover.

Removing the push rod side cover, I also found that the internal ports for the oil feed line normally found under the cover where blocked with threaded plugs.

Turns out that the later block doesn't have the same cast in block oil feed channel to match the earlier '57 head, preventing oil from going to the rockers through the block and a "drilled" head bolt that would normally provide the lubricant path to the rockers in the earlier engines. So for me, that external line is essential to providing lubricant to the rockers and must stay.

It could be your engine is the same, or it's possible that your engine, like many of that period ended up with clogged internal feed path. The Chevy work around fix for that was to install an external oil supply feed like used on mine, plugging those internal ports, and restoring oil supply to the rockers.

I think you made need to confirm what you have for both the block and head to try and figure out what path to follow for getting oil to the rockers. Let us see some casting numbers an date codes from both the block and the head so we can offer more help.