fastest way to upgrade from 8.2 to 8.3

I've got two 300GB databases that I'm going to be upgrading from 8.2.4 (32
bit) to 8.3.5 (64 bit).

The systems are running on Solaris 10u5 64bit with lots of disks in a zfs
raid10 and have 32GB ram.

I've read lots of docs and Google, and found a special flavor of
postgresql.conf that helps the import speed along, but the dump + import
process still takes about 15 hours.

here are the parameters that i've found help in postgresql.conf during an
import:
max_connections = 10
shared_buffers = 32MB
work_mem = 2048MB
maintenance_work_mem = 2048MB
max_fsm_pages = 1024000
fsync = off
wal_buffers = 1MB
commit_delay = 10000
checkpoint_segments = 128
effective_cache_size = 10GB
autovacuum = off

Can anyone give me tips to get from 8.2 to 8.3 faster ?

--

Jeremy Kister
http://jeremy.kister.net./