Confusion around Business Objects clustering

We have installed Business Objects 4.1 SP2 on two times in two different boxes.

Now we want to bring them under cluster in order to have High Availability scenario. Intention is to run 2 nodes together under one CMS and when node 1 goes down Node 2 should take care of the load without any interruption.

Found the below link for Clustering configuration:

Configuring and installing BI platform on server 2 - Business Intelligence (BusinessObjects) - SCN Wiki

This scenario talks about installing Node 1 and Node 2 in one single box and applying the cluster key.

However, my case is different. Here both the nodes are running on 2 Different H/W or Boxes. So questions is: How can i cluster them together?

Can you please provide your insight.

Thanks!!

Tilak