If you aren't spiking much over 3500 bph, I'd for sure keep it in low.  In fact, I wish there was a three-speed elevator drive with a slower one I could use for soybeans.   

Ihles have great product and have never steered me wrong, except when they told me unload auger screws would outlast the horizontal tube 2:1.   That was WRONG.    

We put a bunch of Ihle parts in our 8010 the past couple years rebuilding the feeder house, transition cone, grain tank and unloader.

Everything fit pretty well and went together pretty smoothly other than the unloading auger elbow.    They don't manufacture it, I believe its from Abilene Machine.    Anyway it didn't fit right, we had it next to the old one and did several measurements on it eventually figured out where it was off.  They said all of the ones they had on hand measured the same as the one we had (I sent them pictures of where I was measuring) and they had never had problems with them before.   So I called up the local CIH dealer and asked if they had a new elbow on hand which they did so I went there and measured it. It measured the same as our old one so we took it home with us and put it on the combine.  Fit like the old one did.

Anyway, Ihle treated us well on the deal, they paid the shipping and we returned it for a full refund.   Other than a little extra time we weren't out anything.   It won't deter me from getting parts from Ihle in the future.    They have other stuff that I know we're going to be installing over the next few years.

Couldn’t tell by your pic, is the unloading auger drive fine splined or does it have coarse splines?