Some greys have a multi-speed pto. If your's does, you could try a faster pto speed and a slower rpm and still get around 540rpm at the pto. I think you have enough hp to try it if possible, especially on second pass.
seapea said:I noticed that my skid shoes for my 4' KKII have 4 settings, and were factory set on the 3rd deepest. I went to change them to the 4 deepest when I discovered this is not possible. The gear box prevents the skid shoes from being adjusted any higher.