You might get a better response in the Black/Green rifle forum. I've found Norinco stuff to be generally quite good for the price. They aren't fancy but they work. An upper should fit fine on any milspec lower, but the handguards in particular may not be easy to change, if you have that in mind. Also, the gas block/front sight assembly can be extremely hard to remove...many people find the pins are locked in tight, possibly placed by machine press. However if you plant to shoot the upper as is, it should be good to go.