02 f350 dually overload springs

I have a 02 f350 2wd. I just purchased a lance camper 11ft. After spending 2 day manufacturing a tie down and towing package.(looks a lot like a torklift sys} I relized the original owner removed the factory overload springs,and put a after market front of rear leaf spring hanger on lowering the trk 2" in the rear. it does have firestone air bags on it. My plan is to put 3500 hellwigs on the rear and put air bags back on and replace front hanger with oem hanger.I also will be pulling a 4 horse trailer with the camper . Anyone have any ideas I would love to hear them