upgrade questions

Howdy everyone.

I'm in the process of moving a postgres database from one box to another
and have a couple of questions on the best way to do things.

I'm moving from a RH 6 box using postgres 6.4 to a debian 2.1 box with
postgres 6.3.  It's not backwards compatible, so I can't access the
database at all, except for when I do a "\c <database>" it tells me it's
the wrong version number.

Now the latest debian has the 6.5 version of postgres, but I can't
upgrade to that package becuase the dependancies would break
*everything*.  I could download/compile the postgres sources and build
things here, trying to keep the old directories and directory structure,
and *hope* that that works...

Does anyone know of a good way to move the data across?  Or maybe a way
to convert from 6.4 to 6.3 somehow?

Thanks a lot..

alan