That looks like the same filter adapter as used on the O-200. I seem to recall reading here or somewhere on the internet that this adapter will work on the C-85-12, but not the -8. If that's the case, it might be possible to use the C-145/O-300 adapter which is sorta like a T-fitting which takes the place of the oil screen.
www.fm-enterprises.com just sez c-75,C-85,C-90, and O-200 series. Doesn't specifically mention either the -8 or the -12.
FWIW, I used to change oil at 25 hours with just the screen, when I installed the filter they said you could go 50 hours. That seems a bit long so I go 35 or 40 hours.
Eric