Have you considered using lift spindles? I don't think they make an application for your year truck, but you can convert it to run 88-98 spindles. They make a 6 lug set up for them, and Google search indicates they also make them for the 2500 trucks too.
Read this to see how it can be done
"73-87 2wd lift with 33x10.5x 18 Nittos"