How to compile with different MAXALIGN?

I'm in the process of moving a large database from an in-house Win32
server to a co-located Ubuntu Linux server. The data's in constant use,
so I can't really bring the server down for more than a half hour or so,
and I'd like to go ahead and use a base backup + WAL restore strategy to
sync the servers up before flipping the switch.

After copying over my base backup and setting ACL appropriately, when I
go to start the server on Linux it fails with a message in the log
stating that the cluster (binary copy from the W32 server) is
initialized MAXALIGN 8 and the server is compiled MAXALIGN 4. A search
of the Docs tells me that I can compile the server with a different
MAXALIGN, but the install docs don't give any indication how this is
achieved. Is there a configure or gmake option I can feed, or do I need
to change a line in one (or more) of the source files?

Or is there a compelling reason (I'm absolutely ignorant here) to do a
dump and restore instead of the binary copy because MAXALIGN 4 is better
for performance/security/fill-in-the-blank?

Or is a binary copy move from W to L hopeless even if this particular
issue isn't?

Thanks
Sean