A dual positionable adaptor for a fastener driver assembly employs a tandem guide assembly mounted to a guide head which has an entry reference surface defining an opening for a fastener to provide a proper location and entry angle for the fastener. A pair of wings each defines a pair of reference engagement edges which engage either an upper horizontal member or a lower horizontal member. The wings, together with the entry reference surface, define a proper entry location and angle for connecting a vertical stud to either an upper plate or a lower plate. The selected adaptor position is achieved by securing the adaptor in one of two angular positions relative to the tube axis of the fastener driver assembly. The wings are also affixed with squirrel claws to lock the adaptor in place for installing the fastener. The adaptor also includes flush indicators to indicate that the proper flush position of the reference surface against the vertical member is achieved. The wings are independently pivotal to accommodate situations wherein the tandem wing configuration cannot be employed. The fastener is retained within the adaptor fastener channel via a magnet assembly.