the oiling grooves go toward the head I can't follow your description, it follows the description of this old thread <-Click are you piecing together the heads?
I think all the 426 hemi rocker shafts, both intakes and exhaust , can only go on one way and still oil the rockers like they should I think that if you get them reversed the oil holes, all of them will be exposed away from the rocker arms Maybe not on some brands