Right. You can put it in and the
engine will run. It will probably smoke a lot, you will gunk up your intake and foul the plugs, but it will run.
I sure wouldn't recommend it.
On the other hand, if you're getting the
engine for free, and you don't mind a little extra
maintenance, then maybe it would be worth it. In any case, it is definitely not true that it will not cause ANY issues. Whether or not the issues it causes are worth it to you, only you can decide.