I went to a good upholstery shop with my 94 truck. He gave me good dense foam sized to the seat. I lifted the seat covers, placed the foam and refastened the covers. This was not a perfect fix but the seat were good enough that I kept them this way until selling the truck. I don't know how long they keep posts on this site but there were a lot of threads on this topic for the second gen. trucks. Various materials have been used but I( had the best luck with the proper foam.