I search for solutions in this order: Past Code, Unreal Source, Wiki, BUF, groups.yahoo, google, screaming at monitor. – RegularX
Legacy:ParallelepipedBuilder
From Unreal Wiki, The Unreal Engine Documentation Site
For funky weirdness try:
BaseX: -256
BaseY: 256
weird enough.
then add to that:
InclineX: 64
InclineY: 64
... press build. :D