I have to agree with Perry. I would NOT risk using the results of this DR exercise to make any kind of business decision, even if the result is successful, without first upgrading Node 3 to the same patch level as nodes 1 and 2. If you do proceed, and I was a manager above you, I'd want the DR exercise re-run after the Node 3 upgrade.
Steve (aka sgmunson) 🙂 🙂 🙂
Rent Servers for Income (picks and shovels strategy)