An installation tool for fastening a top plate to a roof support member and other structural connections is adapted to drive threaded fasteners at a pre-established angle. The tool preferably includes a rotary driver assembly and a telescopic tube assembly. A guide head assembly is mounted adjacent the outer end of the telescopic tube assembly. Locating structures function to properly precisely set the drive angle of the fastener. Spaced stabbers prevent the fastener from moving during the installation. A releasable lock mechanism locks the guide head assembly to the end of the telescopic tube assembly. The guide head assembly has a floating guide to align the fastener head with a drive bit, and a wear sleeve for centering and aligning the fastener screws. A spacer collar is dimensioned to set a pre-established penetration depth for the fastener. An automatic release trigger locks the telescopic tube assembly and imposes a pre-established stabbing force threshold prior to driving the fastener and allowing the tubes to telescope.