With shifter in reverse (rod down) and gearcase in forward (rod up) there should be ample room to assemble the connector. Assemble it to the upper rod first. It is vitally important that the notch in the rod is perfectly aligned with the screw hole in the coupler before inserting the screw or the threads will strip. You can slightly spread the coupler with a flat screwdriver if necessary, but usually all you need is a pair of needle nose pliers to “adjust” the alignment. They used that coupler system for ages, even going back to no access door in later years, so it IS possible..