There are folks doing that type of conversion(check on www.hk91.com). I don't think a G36 trigger group works though...unless you wanna go Class III.
There are other G36 parts that work...the foreend/handguards, the optical sight/carrying handle etc. Usually your US parts count would come from the trigger/hammer/sear plus others(gas piston etc). Special Weapons is making a kit but I think that includes their AR-15 mag conversion too.
Yeah, I know about the replica stock and all the other mods. I plan to get one, but first wanted to know if a G36 stock would fit. The answer seems to be no, it won't.
http://alpinetek.netfirms.com/guns/SL8/
this fellow seems to be in the know and well on his way to a
G36 clone. Note the rounded rear end of the the SL8 upper receiver and how one pin attaches the trigger housing grip/stock to it. on a g36 there is a flat upper receiver to acommidate the folding stock.