Today we mated FMY to the BSC/ISI. The fit between the test stand, inside the BSC/ISI, the Genie lift, and the Quad is very tight. Several times, we had to rest the Fold Mirror on the LSAT remove and reposition the Genie in order to complete the operation. We also encountered a fit issue between the unloaded Genie and the gusset plates on the test stand cross member. Once the Fold Mirror was positioned properly under the BSC/ISI, it installed with no problems.