The aft end of the receiver may be one of several configurations ("straight cut" or "slant cut") that can make installation of a traditional stock anything from a breeze to a slight inconvenience (Ironwood Designs makes furniture for most of the variations.)
Shear Stress made a key point on this. You shouldn't slap on a standard
wooden stock because it may wiggle loose while shooting (there's literally too
much stress on it without the receiver meeting up properly on how the stock
is shaped). The receiver is cut back far enough that it doesn't fully top off
the pistol grip either. Stability of the grip is NOT affected, though. It just
doesn't look quite right if you know what a real ak is suppose to look like.
The thicker receiver on the mak also requires some whittling on the stock as
well. If you intend to use a steel folding stock, expect to put in some time
on it and keep in mind the original folding stocks for Eastern Euros don't have
the same screw/tang distance as the Chinese do. It will shake loose if you
can only use one screw hole in the tang --unless you plan on permanently
welding the folding stock block to the receiver/tang. You can whittle a
synthetic stock and you won't have as must wiggle since the tang screw
grooves won't be as permanently compacted under stress like the wood ones
would be.
Leadscounsel, are you back from deployment now? If you want a quality AK go
for an Arsenal or if you want to save some $$$ try to find one of the better
built yugo underfolders --they're still out there and shoot as well as the maks.
If you want to play with retro-fitting a mak, just watch your parts count. But
of course you know this.