I could probably talk my dealer into doing some massaging to my 4520, as one cannot have too much horsepower or torque. I wonder if injector shimming is easy to do or not. It seems the tractor runs pretty well now. I have not driven another 4000 series machine recently and never with all the attachments hooked, so I have little to compare it to. My neighbor says he will drag me up the hill when his 4320 comes in, which is good, as he fared poorly doing it with his current aged 4410. Yes, I did give him a head start. I posed a question in another post about whether other 4000 series machines emit smoke from behind the turbo on startup. Mine does, and I wonder if it correlates with the air restriction light coming on once the tractor has run 10-15 minutes.
John M