Assuming Loop/Tonti swing arm pins? Stainless isn't the answer but anti-seize is. Fortunately if you fudge them up you can get new ones. On mine I was able to soak, heat, soak etc and they broke loose and were able to be salvaged.
Unconnected but a shame still is I just took (this afternoon) a truck load of Guzzi stuff (including at least 1 good swing arm pin) to bulk trash.