A casting shell has: a part cavity shaped for casting the part; a starter/selector cavity below and connected to the part cavity; a connector cavity between the starter/selector cavity and the part cavity; and a support cavity. The support cavity has: a post section; a first linking section linking the post section to the starter section of the starter/selector cavity; and a second linking section linking the post section to the connector cavity, the second linking section having a portion descending from the post section toward the connector cavity.