IF I read the HP correctly for your tractor it is 24.5 or about that. Seems low for that width tractor so I may not have gotten correct hp. But you want at least 6 feet to be wider than tires but if hp is only about 25 I would stop with 6 ft blade and yes it full you will have hard time pulling it even if four wheel drive and not going up hill. So you will learn how much to fill it and how to lower the blade a little and not just drop it in grading. I have a 10 ft pull box blade and not the two feet tall commercial ones with four wheel 91 hp and I stop the tractor depending on what I am grading. If you are going with a blade with the rear cutting blade on it do suggest you get one that swings up when you are pulling forward and only drops down when you are backing up. If it is fixed to me it affects how much flexibility you have with angle and depth when cutting going forward.