If the barrel fits in a standard G1 forend the the G2 should fit also. I'm using the G2 forend on my G1 frame with a SSK barrel and it works fine. I had ask Ed at Ed's contenders about this when I bought the forend from him.
Bruce
Edit: I forgot which forum I was in. My barrel and forend are for the 14" handgun but I would still think it will work.