I agree the 3PH on a M7040 does not lift high enough for my tastes either. But there are some things you can do.
>There is a lift limiting linkage that can be adjusted so the 3PH will lift until the hydraulic pump goes into relief.
Here is a photo of it. It is at the top of the left side lift arm. Adjusting it shorter will allow more lift. If it is too short then the pump goes into relief with the 3PH all the way up and the FEL doesn't work correctly until the 3PH is lowered. The idea is to adjust it just so when the 3PH is all the way up the pump and FEL works correctly. I gained about 6" of lift after adjusting mine.
View attachment 451345
>Also, you can get a second adjustable 3PH vertical lift arm (w/turnbuckle) so
both lift arms can be shortened to the minimum length.
I have a hydraulic "tilt" for the right lift arm and transferred the right adjustable to the left side. Now both sides can be adjusted. That also increased the ground clearance. But you'd get the same effect with two mechanical vertical lift arms. Although a bit expensive, it would save the exorbitant cost of a hydraulic "top and tilt". (Although I highly recommend the T&T. Then when traveling you can shorten the hydraulic top link from the seat and the rear gang of disc pans easily clears the ground...like by 3 feet, or so.)
>You can cut down the solid vertical lift arm so it matches the adjustable arm in its shortest configuration and then weld it back together. That is probably the least desirable since adjustments would be limited.
Just to double check. The lower horizontal lift arm should be set at the hole farthest from the tractor and the vertical lift arm pin should be set in the top hole to get maximum height. Sound like you have already tried this.