You might contact Harvest Services to make sure their concaves have the factory contour. Some aftermarket concaves are "line bored" and do not have a pinch point like the factory ones. I've never heard anyone say how to adjust the line bored concaves. If they are like the factory, use the manual recommendation, which says "The initial position for the concave is with the eigth bar from the left closest to the rotor. When unthreshed heads become a problem, the concave position can be adjusted to the right, moving the seventh concave bar closer to the rotor than the eighth concave bar."