I noticed your post above was numero' uno, so a "welcome to the forum" is in order.
The 8820 is a good machine. The 8820 needs more fan capacity, but every machine has its' weak points. As far as verifying the year model, you should be able to give the serial number to a JD parts guy, and they will be able to tell you the year model of that particular machine.
Sorry, I don't know the differences between the 8820 models, but they have been spoken of (in part, at least) in the above post(s). I think you will like the 8820. A good point about these machines is that they are able to be rebuilt at a decent price. Take a look at the concave, cylinder bars, conveyor augers, elevator paddle chains, and things like that. If these items are in good shape, you will most likely be able purchase a used combine that will serve you well.
The 8820 is a good machine. The 8820 needs more fan capacity, but every machine has its' weak points. As far as verifying the year model, you should be able to give the serial number to a JD parts guy, and they will be able to tell you the year model of that particular machine.
Sorry, I don't know the differences between the 8820 models, but they have been spoken of (in part, at least) in the above post(s). I think you will like the 8820. A good point about these machines is that they are able to be rebuilt at a decent price. Take a look at the concave, cylinder bars, conveyor augers, elevator paddle chains, and things like that. If these items are in good shape, you will most likely be able purchase a used combine that will serve you well.