Ok , I'm on the hunt for my first AK . I know where a MAK90 is has all Norinco marks , stamped receiver , and a thumb hole stock that's so crude parts of it are almost square. But it's as original as any I have seen , I know the owner and it has been shot very little

Questions - can these take a side folder stock ? Any special type needed ?

Do these take any standard AK mag ?

I already looked at it , and it is in very good shape - looks new

Any disadvantages ?

Yes it will take standard AK mags. You have to check the rear of the receiver to determine your stock options as some MAK 90`s had the rear of their receivers slanted.

Ace ltd makes a nice folder.
The only dis might be the blued finish isnt the most durable (but could be touched up)
maks have some of the best triggers

I put one of the eastern European folders on mine. I had to file it a little because the walls of the receiver on the macs are a little thicker. pretty easy to do though. only one screw hole lined up as well.

Yes. Works like a charm.

If you can take off the buttstock, do it, and get a good look at the back of the receiver.

Mak-90's have a few variations: http://ironwooddesigns.com/IWDreceiver.html

I just ordered a Bonesteel Galil-type folder for my 2nd MAK90.  Reviews look excellent and it is designed for the thicker receiver.  Maybe a tad pricey, but the closest thing I can find to one of those Bakelite folders.