Left is the green hub fan off my Hdj81, right is a blue hub for a later 80 series I picked up at a swap for cheap. green hub is still running nice, but the fan blades look much smaller and I wonder if the fan blades off the right later fan would push more air than those on the original left. I don’t have much time to change the viscous hub oil inside and the “blue hub mod”, but the blade swap I can do quickly while it’s out. Any input or experience!