That part number is NOT supposed to be for oil through pushrod. You keep saying "LA style oil through pushrod provisions" but you must look carefully at the part numbers. Your part number is LA oiling through the head, into the rocker shaft, and then to the rocker arms. There is a different part number for the oil through pushrod rockers, but it is only different by one digit.
Part number S72026K is for oiling through the pushrods. Notice the third digit is a two, not a zero.