Well your 4105 is only 2 inches longer than my
B3200. Seems like a short wheelbase for a larger tractor. That being said - I would rethink on the reasons you need such a heavy bucket. Change to a lighter bucket. Fluid in the rear tires would help. Acquire lots of ballast. Run in the lowest gear traversing the slope.
I recently visited a tractor junkyard where I found numerous tractor ballast pieces. I selected two flat pieces that I U bolted onto my rear tool bar which is similar to your ripper. They were inexpensive and bolted right on. I could opt for more ballast just by using longer U bolts.