gcspray: Did you end up going with the HD trans? I'm interested in what you think of it.

Our Expy is the same as yours other than it's a 2000 EB. We bought it used to replace a POS Chevy Tahoe that was purchased new and babied. The two do the same work: 80% towing a 2 and then a 3 horse trailer. You can tell your shop friend the Tahoe couldn't even handle the light 2 horse trailer

We've re-done the air suspension, an alternator, fuel pump and a drivers window motor/winder and otherwise regular maint. While it gets good mechanical maintenance it sits outside all year and still has shiny paint. Since we tow with it so much, I do drain and fills on the trans every 10k miles or so: 6 qts out and 6 in -- switched to Mercon V a couple of changes ago, also do 5k mi. OCIs...

I'll be interested to know what you decide to do transmission-wise as if ours ever goes I'd consider a built up one too.