On many years of Dyna's, the front exhaust header is slightly lower than the frame rail causing pressure on the pipe and/or uneven rest on the jack. I cut a square of 3/4" plywood that fits across the lift arms, and butts up to (but not under) the head pipe. Both frame rails sit on the plywood. It takes careful alignment and maneuvering, but the bike sits straight and is steady when lifted. Of course I can't chance oils on the lift, but I prefer to do that on the floor anyhow.