At 60 bu, you should be getting 2 or 3 hoppers off in an hour. Must be really tough thrashing? Id say you're close on settings. Fan and cylinder speed as high as they go, close concave as much as possible without cracking. We always kept chaffer closed and sieve at about 1/4 inch.

 

Have you opened the door on the return by the cab door to see how much your getting in it? May have to open the top sieve and close the bottom a little bit more. I usually put my cylinder at 2 as well, but I keep the cylinder speed at about 1000 and fan at 1100 so pretty close to what youre doing. I was cutting some 70 bushel hard what at 4.5 to 4.8 mph and leaving nothing on the ground. Im using a 25ft header too though.

 

Won't be setting any big record in heavy wheat if you have to cut it on the ground. I have the concave rear pinch set until it ticks, front would be maybe 1/4" from the rub bar indicator says 0. Run around 780 to 900 cyl speed It was testing 11% to 13% we were down at the lower speed for the 11% stuff. Sieve is set to 2 or about 1/4 inch, this one has the notched handle adjusting kit. You should be able to push through 600bu/h max it think. 50 rpm Cyl speed makes a huge difference in the cracking on those things. You guys run way too high a speed and too loose that is why the wheat goes out the walkers. Remember cylinder speed not concave clearance has the largest effect on cracked seeds. Thresh it once hard at the front as much as possible. And to do a decent job in wheat you should have the 1st 4 concave bars blanked off I only blocked off the first 2. We are running 3-3.5 mph in 30ft swaths. Not huge swaths either droughted out and not cut on the ground doing 2 dumps an hour.
Keep in mind John Deere conventional concaves work a bit different. Their pinch point is near the middle of the concave the back half of the concave is basically a separating grate so this doesn't give time for a lot of rub bar hits to smash the grain out. Basically they are a short concave to get this all done in a short period of time.