Attaching volumes to a SQL Cluster 2005

We have our production SQL 2005 server (64 bit Standard Ed.) attached to an iSCSI Equalogic SAN. We have set up 2 new servers and installed the cluster service. My question is: can I install SQL 2005 in this new cluster environment an latter on disconnect the data and log volumes from the production server, attach those volumes to the cluster an reattach the DBs? the reason we need to do it like that is that we don't have enough spare space in the SAN to initially create these 2 volumes in the cluster.
Any ideas/suggestions would be greatly appreciated.