I feel I should point out a few things that I have seen which were similar to the Aussie post which talks about KB oiling problems.

IMO, it's up to the builder to check what you have. You just can't assume anything, regardless of where it comes from. For example:

* KB block castings do not have lifter oiling so they have to be gun drilled if that's what you need. That process can hit the oil feed oil that would normally feed the head from the #4 cam bearing. A problem? - sure, but detectable and fixable before you get started.
* That gun drilling can be blocked off later if you install or relocate lifter bushings. I recently built a motor where I had to run oil lines in the lifter valley to get oil to the front of the oil galleys. A pain again?, sure, but again fixable.
* The gun drilled galleys are normally fed by oil that goes around the #5 cam bearing via an extra groove. I asked Ken at KB to prepare the block for 60mm roller cam bearings (I even sent him a bearing so he got the bore correct). When they enlarged the holes that they inadvertently removed that extra oil groove. I had to feed the galleys from an external line. A pain again, sure, but fixable again.
* The head feed holes that normally go to #4 cam bearing where blocked off by the shell of the roller cam bearing. So I added separate oil lines directly from the back of the block to feed the heads.

You have to check EVERYTHING. Ken stands behinds his product but the market has clearly stretched his ability to keep up with the QC. The good news was no major machining was required and everything could be fixed as long I spent the time to check everything before assembly.