An interface for a gas turbine engine. The interface includes a full-hoop vane ring around the engine axis, the full-hoop vane ring comprises a forward vane rail with a vane ring forward contact surface and a vane ring anti-rotation tab, the vane ring anti-rotation tab engaged with the anti-rotation case slot; and a multiple of BOAS segments around the engine axis, each of the multiple of BOAS segments comprise a BOAS aft engagement feature and a BOAS aft contact surface, the BOAS aft engagement feature engaged with the outer case and the anti-rotation case slot, the BOAS aft contact surface abuts the vane ring forward contact surface.