To get the most 'jam' from the pan, you need a THIN fluid, not thick. GASOLINE.
It will move downward through the block quickly, and the faster it moves, the more jam it will carry with it. AND, gasoline will solve even carbon deposits on pistons and head surfaces (except for yours being redone), so you know it will loosen the Campbell's chunky jam in the pan as it moves through.
All the vapors will be gone by the time you pull the trigger, so that's not a problem either...
Did you push a pipecleaner through the pushrods?
Good call dumping the Dex-crudge. Been there did that x 4, including one bought NEW '02 Express.
When you pull the trigger first time, leave out the plugs. That makes the new oil really flow good, with no fire.
Little late now, but every time a part gets out of the way, the bolts go back in the empty hole, til it's time to chase/clean the bolt and hole. Bolts never get lost that way, and you think more about each part - good for the noggin'.