Assuming you have the same Mud Hog we have, you can get 28l26's to fit if you space the motors back. When the right tire is turned into the return auger, it also gets closer as it moves upward. To accurately see how close your tire is, you need to take the left tire off and jack the right one up in the air until the axle stops make contact. You may find that things are closer than you think. To my knowledge, the biggest tire you can get on there without doing modifications is the 18.4-30. Marvin Gorden has a set on a 1680. luckily, the modifications are quite easy and I will get you the info if you want to do it. Mike