This is for oil through pushrod rocker? Only way I know to do that would be to tube the galley and then drill small holes in the tube at each lifter, unless there is some way to limit oil going to the galley on each side.
For shaft rocker oiling like on a normal LA head, you can simply isert an orifice into the block or the head on the passage that feeds the rockers.
Maybe you should ask Indy how they suggest going about it.