Yes sure the reason for that Hollander statement is only related to what Transmission that you plan to use. So if the engine you pick up was being used with a Stick / or Manual Trans behind it then it will have the Pilot Bushing in the Crankshaft Center as well as a Manual Trans Block Plate Spacer, a Flywheel, and a Clutch Assembly. And say your going to be now using that same engine but with an Automatic Transmission. Then to do that you will need to remove the Flywheel, the Manual Trans Block Spacer Plate, and the Polit Bushing also needs to be removed from the Crankshaft. In order for the Auto Transmission's Torque Converter Hub to be able to then seat into the center of the Crankshaft and also bolt up correctly to the Flex Plate it is necessary to remove that Pilot bushing!
Now as you said above you are going in the opposite direction and the engine that your picking up was using an Auto Transmission before and you now need to change it over now to a Manual Trans. So to start you will need to remove all the Auto Trans parts if it comes included with them as follows, unbolt and remove Trans at the Bell housing off the back of the engine, remove the Torque Convertor from the flex Plate, then the Auto Trans Flex Plate off the crankshaft, and finally remove the Auto Trans Engine Block Plate Spacer. After that you are ready to install a new Pilot Bushing, then install the correct size Manual Trans Block Plate (there are 2 different ones), and then install the correct Diameter & Ring Gear Tooth count Manual Trans Flywheel, plus the correct Clutch assembly (there are 2 sizes 8.5 or 8 inch) each only fits in one of the two most common sizes of Bell Housing and fit a certain type Manual Trans too. Good luck on your swap it will be an easy bolt in job with the right parts that you all ready have on the 144 or 170 Six that's in your Econoline.