This is not a great picture, but if you can make it out, it demonstrates what a side oiler looks like on the outside. This picture is of the left/drivers side from underneath the engine. There is an
oil galley that runs down the side of the block just above the pan rail. Then at the 3 center main bearing webs a hole is drilled through the side
oil galley to the mains. This hole is capped with a pipe plug
Some C/O's had the S/O casting but not the machining and some builders have been known to add the side plugs in these castings to give it the "appearance" of a S/O. The only way to know for sure is to remove one of the side plugs and verify that there is
oil there
Craig