Arlon,
I bought a 2'x6' piece of 1/4" aluminum for a skit plate. Covers the oil pan, trans and x-fer case. Cost about $150 in materials and to have the shop that cut it to size, add three bends in their press. Then a few holes and some brackets and everything from behind the radiator to the trans cross member is covered.
I suffered form a lack of power for a long time, I finally tracked it down to the AMM. $45 Amazon unit later and it runs perfect. I run 235/75-15 Firestone Destination A/T's w/ the same rear end you have.
If you want an Astro, I think the 2003-2006 (the '16'er) is the way to go. I'm sure that's what Herbie and T.Lowe (?) have.
John