okay, thanks for clarifying. but I still find this question interesting. I've seen much more wild ideas, like fitting an a1200 in an a600 case etc. A ppc'ed cd32 would be fun 
Think twice. What software should or would make use of it ?? Games? None of the PPC games are running without gfx-card. All are crashing on aga.
What 68k soft would benefit? None either, they are all build against original machine.
As mentioned somewhere before, small brainers don't learn from asking once or a dozen times. And people with ADS don't accept "no".
Because of the nature of this question, it can be adjusted to any other non-working combination of hardware, endless repetition of why or would will follow. This is the nature of trolling caused by boredom.