I've got the T-belt/waterpump swap down to 2hrs (electric fan saves a bunch of time there). once you are torn down that far, aside from the timing covers just install all new parts.
Tranny is much easier to get to on a lift, but if you have enough suspension lift/tire you can crawl under the truck and be comfy enough to do it. I did my tranny filter in my service, couldn't drop the pan completely because of the exhaust, but manuvered it just enough to reach all the filter bolts and dump the littl bit of fluid that didn't drain as well as clean the fuzzy magnet .