Actually from what I have read the Dart blocks need some extra work to them that the R blocks do not need. Both blocks need lots of finishing work no matter what, that was fully expected. But when the inital line hone is off and I have a few lifter bores that are already to big I expect Ford to make it right and not have it left to me to fix their issue. Not sweating it to much, heck I might use this block anyway since the deck is so good on it.