A rotor disk assembly comprises a first rotor disk with a plurality of circumferentially distributed first throughbores. A second rotor disk comprises a connection portion projecting at least partially axially, a plurality of circumferentially distributed second throughbores being provided in the connection portion in cooperative distribution relative to the first rotor disk for the first and second throughbores to be in register with one another in the rotor disk assembly. Connector bolts each have an elongated body with a flange between its ends, a head at its first end and a removable head at its second end, the head at the first end spaced apart from the flange for the connector bolt to be secured to one of the rotor disks at a respective throughbore, the removable head at the second end being spaced apart from the flange for the second end to project. An anti-rotation feature is between each said connector bolt and at least one of the rotor disks to prevent rotation of the connector bolts when the removable head is installed on the second end in the rotor disk assembly.