Don't know what thread spec the Norinco frames are tapped for, but make sure the major diameter of the Norinco threads is the same size (or less) than the minor diameter of the new threads.
Otherwise, the tap drill for the new threads will not remove all of the old threads and the strength of the connection will suffer. There's only about 6 threads in the grip bushing hole on a M1911A1.
Just tossed that out as something to consider.
When you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind. [Lord Kelvin]