Hi, gman.
I installed logic 8.0.2 onto a new mac mini running Mountain Lion using Pacifist. It costs about $20. Just google and you'll find links to its site.
This program will open and load all the install files from all the LP 8 discs and let you install onto ML. Just click the relevant installer from the list. I didn't reinstall the content, but all the other installers worked without problems.
The only issue I had was the Audio Unit Manager's Avualtool crashed whebn it tried to vadilate all my Waves Mercury plugins. I suspect the problem was the processor being too fast for that program. After about 25-30 vaildaditions it crashed Logic. A restart and another try got another 30 or so.Once all were validated there was no problem loading LP 8 or opening projects.
You might have problems depending on file sizes, but at least you can try LP 8 before using LP 9
Hope this helps and you get up and running
Regards,
Scorpii