1 3/4 thickness is ok Tom, it's not really a flex thing, it's the unthreaded portion of the studs in the gimbal housing, 2 1/2 of unthreaded stud, the inner plate is 1/2 and then there is a thick washer goes under the nut on the stud. If you think the stud nuts are going to bottom out, you can use a 1/4 shorter bolt, rather than the studs.