rolf,
I have a 59 261 in my truck, the oil line is under the lifter side cover and comes from the rear cam bearing up to the center of the block. If you look at the block (in the shop manual) or on the head gasket you will see a spot were the oil will pass up to the head and the tube on the center of the rocker arm shaft the feeds the arms.


Tommy
59 apache 1/2t
261 short stepside