all these ways are doing the same thing. A eng. have a problem when you use rollers. the lifter wants to uncover the oiling hole in the lifter bore and that is a problem [no oil presure].
if you have a eng. book from MP you can read all about the right side oil feed block off.
if you bush the lifter bore you do the same thing as blocking rt.side of block.
in the other post you saw the bushing deal was because there was to much clearance in the lifter bore. there are a couple of companies that have roller lifters that you dont have to do any of the things. as you know things dont always work like they say. that is what the bushing thing was about in the other post.
dont know if that helps any or not.