Crap - returned the darn things about an hour ago and didn't measure diameter.
While I can't get you a diameter check (fit on the Mellings was very snug though), I remember putting the Melling lifters next to the "good" lifters in the engine (same comparison as is made in the video), and the hole location and the chamfered oil ring were dead on in the same locations across the length of the lifter (even though the oil hole was 90 degrees off).
