Rusty,
Thanks for the clarification. I was pretty sure from your posts that you were pushing the max capacity of the loader, but could not decided if you felt you were getting everything you should out of it. If I have understood all this you feel like the loader IS performing to spec, you just wish you had a little more umph. I have no first hand knowledge of anyone going to bigger cylinders on this particular model. If spec'd preperly, I doubt there is much risk by going a little bigger. My only concern is the front axle. There have been issues in the past where people have chewed up front axles with heavy loader work. Skipmarcy is an expert at changing those out. I might have a cylinder print that would give you the retracted length, stroke, etc for you to see about getting some custom built.
Oh.. and don't ask Erik... Your's is still under warranty...