those should be all the same. the only things i can think of that might be changed are the radiator and electrical system and fuel system and possibly the main pulleys off the engine might be a different diameter due to the diesel running a bit slower.
I've swapped unloading auger and straw walkers off gas 4400 to diesel 4420. Straw walkers are exactly the same. Still have a couple here, combine is gone. Unloading auger was shorter than the '20 auger, and different mounts, but all I wanted was a nice straight tube!