B-1B Guy, Thank you for the post and update, and good to hear you got things sorted.
In HD's since everything is all together, there is no shaft exposure to attach adapter to pre-presurize everything. Sorry, I am new to this V-Twin biz, and it sure is helpful to understand and learn things.
It makes sense, when rebuilding automotive engine "dry" it was easy just to use a drill motor to spinup the oil pump, and prime the oil pump for a "wet" engine, prior to installing and startup of the engine.