I was planning on doing the same for my M931A2. Like the link to the other thread states, a lot of the typical over the road air bag system leaves a lot to be desired for off road. I have a complete 2000 freightliner with air bags that I could use but I think it would be a down grade. The walking beam set up is the best for off road and the most durable, thats why you see it on dump trucks, concrete trucks etc. The best set up is the air ride walking beam but like the other thread also said they are hard to come by. I was thinking of leaving the leaf spring system but remove all but the last 3 leaves then add air bags. At least that way you wouldnt have to redesign the whole system. But first it might be better to add an air ride cab to see if that may be enough of a ride improvement.