I recently picked up a '91 FLHTC. The tour pak has gone missing somewhere in it's history, but that's OK. I have a 4-bar luggage rack with a back support for the other half, but I 'll be damned if I can figure out how to mount it to the bike. I am new to this model, as my other bike is a '98 sportster. Someone told me that there is a sub-frame tube / bar missing from the back and the rack should mount to that. I have the factory parts book and repair manual but I can find no mention of such a piece. Does anyone know a part no. or where I can find one so I get can this thing set up.