EDIT: First, do a pull with everything setup exactly like before. Because if you lower acceleration rate your results (Torque and WHP) will increase
and you want to do side by side compare of the headers first. But after you do that maybe try lowering accel rate as outlined below.
For next dyno pull, I suggest you ask what the dyno acceleration rate is set at? I suggest 250-300RPM per second and no higher than that, this gives the engine stability during the pull. I can't tell from the screenshot how the dyno was setup.