Norinco made the sks-m and sks-D both using ak mags, as I recall they had some modification to the bolt in order to get it to clear the feed lips properly, I have a buddy who has the mag well off of one, it requires quite a bit of modification to get it to fit correctly, and afterwards (at least in California) you are pretty screwed if anyone sees it.
one of my other friends in order to keep his SKS-M after the ban passed, converted it back to regular SKS fixed mags, but as a side benifit, you could still use it with AK mags, you just couldn't remove them and you had to pull the stock off to put them in. still, the 75 round ak drums worked great in it and wern't banned as they were not detachable magazines.
the short answer is don't bother with it, its more work than its worth and odds are you'll wind up with a screwed up rifle