don i am also in the middle of a rebuild, my 235 is a 60 and the head is a 55. i have an oil line ran around the head to oil the rockers just like in your picture. i do not have the line behind the push rod cover. also even if i had that line there is not a hole in the bottom of the head to let oil up from the block.
should i just leave the external line or drill the head and
install a line behind the rocker cover? philip