I did not check it at SourceLink but I remember for Solaris 5.8 there are a bunch of patches required for 5.4.1. I am not shure if 6.0 or 6.1 runs at all on Solaris 5.8.
IC6.1.3 works fine on Solaris 8 .
But unfortunately that is not a case for MMSIM 7.0...7.2, since they need some libraries from Solaris 10.
According the Sorcelink, Solaris 8 has been excluded from the support line.