A spinal surgical system, comprising: a connecting member including an elongated body having a length sized to extend between at least two vertebrae (V1, V2, V3); and an anchor assembly including a distal bone engaging portion engageable to bony structure and a receiver extending proximally from said bone engaging portion, said receiver including a passage between opposite side portions (66, 68) of said receiver with said passage opening at opposite sides of said receiver and with said passage further opening at a proximal end of said receiver, said anchor assembly further including an extension having a pair of elongated arms (20, 22) extending along a longitudinal axis from a proximal end of said pair of arms (20, 22) to said side portions (66, 68) of said receiver, said extension including a distal ring portion connected with said pair of arms (20, 22) so that said ring portion extends around said receiver with said ring portion located distally of said opposite side openings of said passage through said receiver and a distal end of said ring portion located proximally of a distal facing surface of said receiver from which said bone engaging portion extends, said extension further including said pair of arms (20, 22) extending on an outer side of respective ones of said side portions (66, 68) of said receiver so that said pair of arms (20, 22) and said ring portion removably connect said extension to an outer surface of said receiver, said pair of arms (20, 22) defining a space therebetween that extends to said proximal opening of said passage of said receiver, wherein said space and said passage are sized and shaped to receive said connecting member therethrough so that connecting member is movable from said space through said proximal end opening of said receiver into said passage, wherein each of said pair of arms (20, 22) includes a planar inner surface (21, 23), said inner surfaces (21, 23) facing one another and extending parallel to one another and parallel to said longitudinal axis, wherein said inner surfaces (21, 23) define a receiving portion adjacent said proximal end of said pair of arms (20, 22) where said inner surfaces (21, 23) are separated by a first distance; said inner surfaces (21, 23) define a tapered portion (31, 33) extending distally from said receiving portion where said inner surfaces converge toward one another to a proximal end of said receiver; and said inner surfaces (21, 23) define an alignment portion (35, 37) extending along and forming a parallel extension of said passage of said receiver along said opposite side openings of said passage of said receiver, said inner surfaces (21, 23) being separated by a second distance along said alignment portion (35, 37) that is less than said first distance. a connecting member including an elongated body having a length sized to extend between at least two vertebrae (V1, V2, V3); and an anchor assembly including a distal bone engaging portion engageable to bony structure and a receiver extending proximally from said bone engaging portion, said receiver including a passage between opposite side portions (66, 68) of said receiver with said passage opening at opposite sides of said receiver and with said passage further opening at a proximal end of said receiver, said anchor assembly further including an extension having a pair of elongated arms (20, 22) extending along a longitudinal axis from a proximal end of said pair of arms (20, 22) to said side portions (66, 68) of said receiver, said extension including a distal ring portion connected with said pair of arms (20, 22) so that said ring portion extends around said receiver with said ring portion located distally of said opposite side openings of said passage through said receiver and a distal end of said ring portion located proximally of a distal facing surface of said receiver from which said bone engaging portion extends, said extension further including said pair of arms (20, 22) extending on an outer side of respective ones of said side portions (66, 68) of said receiver so that said pair of arms (20, 22) and said ring portion removably connect said extension to an outer surface of said receiver, said pair of arms (20, 22) defining a space therebetween that extends to said proximal opening of said passage of said receiver, wherein said space and said passage are sized and shaped to receive said connecting member therethrough so that connecting member is movable from said space through said proximal end opening of said receiver into said passage, wherein each of said pair of arms (20, 22) includes a planar inner surface (21, 23), said inner surfaces (21, 23) facing one another and extending parallel to one another and parallel to said longitudinal axis, wherein said inner surfaces (21, 23) define a receiving portion adjacent said proximal end of said pair of arms (20, 22) where said inner surfaces (21, 23) are separated by a first distance; said inner surfaces (21, 23) define a tapered portion (31, 33) extending distally from said receiving portion where said inner surfaces converge toward one another to a proximal end of said receiver; and said inner surfaces (21, 23) define an alignment portion (35, 37) extending along and forming a parallel extension of said passage of said receiver along said opposite side openings of said passage of said receiver, said inner surfaces (21, 23) being separated by a second distance along said alignment portion (35, 37) that is less than said first distance.