The only advise I have if your pulling stuff with that grizzly is to use low gear !! You will take out the one-way bearing that controls your engine braking. dont ask me how I know this -haha my griz 700 is at about 3800 miles so far and I am an expert at changing that bearing now.
That's interesting Jack. One thing I will say though is that when we pull logs (on the dray) out of the woods we rarely even have to use 4 wheel drive. It simply pulls that easy, so I see no reason there should be a problem and why a problem with that particular bearing. However, your griz has a few more miles than ours. 99% of the miles put on it is right here on our own place doing work.
I might add that about the only time I use low gear is when pulling equipment working up ground. Then it is a must to use low range.