Variations in extrusion speed or flowfront shape across the outlet faces of honeycomb extrusion dies are predicted from variations in die geometry across multiple die extrusion zones, based on data correlating the variables to the variations in extrusion speed or flowfront shape, or on calculations of the pressure drops to be experienced by extrudable materials traversing the extrusion zones, adjusting the variations through die processing as desired to appropriately modify die geometry prior to use of the die in an extruder.