I don't know if you are legally allowed to do so, like MacOSX cannot legally be installed on white box pc's (even though it works).
Secondly, nothing is know about what check hpux does in hardware before it boots, could be that it requires some kind of this or that, which is normally not found in other itanium boxes.
Other then that, if all the hardware (controllers etc) are supported by hpux, i don't see a reason why it shouldn't work.
