From what I understand of the new lifters, up t just over .600 lift, no, you dont have to limit the oil to the lifters, but, if you are running .650 lift or more, they still suggest blocking off the lifter galley because the lifter wheel will still be pushed up into the oil galley. There is no way to stop from uncovering it past a certain lift.

You also have to block the drivers side galley too, or it will dump oil pressur too, but this is a lot easier to do. All of the oil is pumped directly into the passenger side galley. This galley interconnects with the mains and this is how they get thier oil. The drivers side lifter galley gets its oil from the front main. Oil is fed down to the #1 main from the passenger side lifter galley and then crosses over with an interconnecting passage to the drivers side galley. To stop the oil from getting there, you either tap and plug this passage at the main or drive a plug in the galley under the cam plate back far enough to cover up the feed hole.

Once again, if you are using pushrod oiling, you have to bush both sides of the block so that the lifters can get oil.