Yes CSPPC fits just like MK3. But I would not recommend it since there is so small space and you may have overheating problems. For A3000 I think the best card is MK2.
I have no problem with overheating with my A3KD CSPPC 233 MHz, and I throw everything at it, OS 4.1 included.
There's a slight case mod required, you want to cut away (I just cut & peeled over) the metal above the CPU fan. It wasn't hard, I did it before day one as I knew that would be an issue otherwise. A hacksaw and pliers were all I needed.
Never had a problem since. If you leave the floppy cover off the 3000 fascia, then there's adequate cooling for the PPC with the fan exposed, at least in my experience.
LOL! Sorry, I just re-read the OP. "Without case modding." Then yes, I agree with the above post that the CSPPC is just too crammed against the metal frame for long run sessions. Apologies for misreading that. That said, it's a pretty minor edit of the internal frame and is not at all visible. If you cut it away (instead of peeled like I did), you can even put a floppy back in there if you ever go back to stock.
