Abstract: The disclosure relates to a paint spray system and specifically to a novel part gaging apparatus and spray head positioning system. The paint spray system comprises a spray housing, conveyor means to transport a workpiece to be painted through the housing, and spray head means mounted on a movable positioner adjacent the housing and extending into the interior of the spray housing. The part gaging apparatus includes a part sensing element positioned adjacent to the conveyor means and displaceable to contact a workpiece being conveyed to the spray housing. The part sensing element is mechanically connected to a position memory apparatus and operates the position memory apparatus in accordance with the distance the part sensing element is displaced. The displacement information is appropriately related to the width of the workpiece and establishes the proper forward position to be occupied by the spray heads of the coating system.