I have to go to work now and someone else will be along soon to help no doubt. If the CS PPC card is good without a doubt then you should be able make it work, but it might take some research.
I seem to recall having to change some settings in the CS PPC early boot menu. I think the ram speed has to be set to 70ns and perhaps turn off Maprom if it is enabled. I think I also had to turn off LUN for the UW SCSI controller. Try holding down ESC to get the CS boot menu.
There are lots of people here who have Classic OS4 running. Keep Trying and Good Luck!
-Jeff