^^^ This..... and if you groove the bores, it only makes sense to me groove up on the top (towards the valley). I figure doing it on the bottom (gallery side) will result it in most of the oil just running off the bottom edge of the lifter and dropping down in to the crank area. I personally would not extend any groove to the top of the lifter bore, just high enough to be at the level of the lifter waist band when on the heel of the lobe.... which looks like what they indicate.