Hate to dig up old threads like this, but this has shown up prominently on several google searches I've made, and I just wanted to try and clarify on this so the wrong information isn't spread around =P
Now I'm not a VH45 or JDM VH41 expert, but I have done a ton of research into VH45's for several swap I would like to complete (one of which happens to be into an older skyline, has to be 25 years or older to import to the states, and the VH45 would be a legal engine for a swap =D).
The USDM VH45DE is hardly a bucket of shit compared the JDM version. Now the comparison of a USDM VH41DE to a JDM VH41DE, the description would be very accurate. The only thing the JDM VH41 has over the USDM VH45 is the addition of a duplex timing chain, so the heads are a little bit better, but not by a whole lot of difference. Now granted down under, the availability of the VH41 should warrant the simple building of the VH41 using the rotating assembly of the VH45.
The USDM VH41DE is a fairly poor engine however compared to both the VH45DE and the JDM VH41. The USDM model did not have a crankshaft girdle, poor flowing heads, poor exhaust manifold design, and is generally much more poorly designed engine compared to the other two engines.
Again, I apologize greatly for being a grave digger, and it is certainly not something I do often =P I just wanted to say something as this thread has shown up in several of my google searches and I figured it might be worth noting that this information is not exactly correct!