They don't reproduce the 340 mount that I'm aware. You have a mismatch of parts. 67 A body, 73 K member. What motor mounts are you using?
We just worked with a friend that has 318 mounts on a 71 E body with a 340. It was low on the passenger side. We used body shims between the mount and the insulator to level it. It can't be seen once installed and tightened.