The Bloch line (BL) racetrack memory (RTM) has recently been proposed as a novel device to overcome the problems of the conventional domain wall (DW) RTM such as stochastic shift and high shift threshold current due to process-induced roughness. In this work, we assess the performance of BL RTM memory cells by conducting circuit-level simulations. A micromagnetics-SPICE hybrid simulation framework is proposed and implemented as an optimal solution to guarantee both computational efficiency and micromagnetics-level accuracy. The feasibility of multibit BL memory operations is demonstrated as the stochastic Landau-Lifshitz-Gilbert (s-LLG) and Monte-Carlo (MC) simulations are carried out at room temperature to take into account the temperature effect and process-induced device mismatch. Furthermore, some crucial considerations in designing and optimizing the BL memory are addressed.