I didn't do the Moss kit, but made my own reinforcing gussets, as others have done. It seems the large mass of the 3000 engine creates forces on the engine mounts that can create small stress fractures in the frame fore and aft of the mounts. Welding in gussets works to stiffen the mount in the direction of flex AND distribute the forces over a larger area = less localised stress on the frame. I think.