please, do not use mod_cluster 1.1.3, go for 1.2.3+, a lot of good work has been done there.
Furthermore, take a look at this post of mine I created several minutes ago. You will find it helpful :-)
hm you want to encrypt the connection from AS to httpd on need to configure the AS part (ssl element in the modcluster subsytem).
No, I don't want to encrypt the connection from AS to httpd. We only want to encrypt from client to httpd.
then it is a normal httpd mod_ssl configuration.