I have an 1100 in 2 3/4" that I bought in 1974. Unless it is a 3" action, it wouldn't do you any good to put a 3" bbl on it. You might want to replace the barrel anyway. As I remember, there was a recall on the barrels back in the 80's. I didn't send mine in, but bought a new barrell in the late 90's for it because I wanted a Rem choke.