RV Repair: Sagging springs, firestone airbags, ford e350

Question
HI Ron,

We have a '91 Tioga Class C on a Ford E350 chassis. It's sagging in the back and we tried to have some air bags put on but they said there wasn't enough clearance, and wasn't sure there ever was. Which makes me question whether they couldn't put them on because of sagging? Maybe it's the vehicle design?  I contacted someone on this site and they suggested re-arching the springs or replacing them. Replacing them is very costly and it's been suggested by several shops around here to use helper springs. I would estimate that it's sagging about 2'3".

Can you offer any advice regarding them?

Answer
Since I am the only one that answers rv questions, it was probably me and my advice is still valid.  I just had the rear springs re-arched on my 98 Winnie, added an extra long spring on each side and that should last for awile.  While I was at it, I installed a set of Firestone airbags for times when the coach is fully loaded. It cost me $ 250 to have the springs re-arched, $ 250 for the airbags so for $ 500, I saved a bunch over new packs of leaf springs.