In 59-62 the holes in the rockers do not line up with the holes in the shafts. They require more pressure to then weep out though the clearances. If you can get the oil passage to supply enough pressure, it should work. The 59-62 rocker shaft does not dump at the connector in the middle, thus pressurizing the rocker shaft and ensuring all the rockers get oil to the weep holes.

1947 3600 Chevy