A connector block for an implantable controller. The connector block includes a first pair of side-by-side bores extending distally from a proximal end of the connector block and defining a major longitudinal axis. A second pair of side-by-side bores extends distally from a distal end of the first pair of side-by-side bores, each of the first pair of side-by-side bores defining a first diameter and each of the second pair of side-by-side bores defining a second diameter less than the first diameter, each pair of the second pair of side-by-side lead bores include a setscrew bore sized to receive a setscrew and being transverse to the major longitudinal axis.