A Bach 4G requires serious chops.
I found the Denis Wick 6BM / 6BS (reasonably close to a Bach 6 1/2 AL) worked well for me originally shifting to New Standard and older Bessons from my Conn.
More recently I have found a BB1 EU working well for me on the Bessons without reducing my upper range.
Of course, I was dealing with medium shanks and you are probably dealing with a large shank on the 967.
Jim
Jim Babbitt
1960s 4 valve and 1971 3 valve Besson New Standards (Denis Wick 6BM) for regular playing
1936 Conn 5 valve 30I Double Bell (Bach 6-1/2AL) General Purpose Back -Up
1924 Buescher 5 valve (the Denis Wick is close) and 1940 Holton 5 valve (Bach 6-1/2AL) Double Bells for kicks.
1860s OTS Saxhorn when history is required (the Denis Wick fits)