The 58 year old Firestone Power Implement tires are in excellent shape with little wear and no cracking. I set the MK0 front tire up against my MK1 Firestone to show how much more tread they have. These are 4 ply rated and probably would work great on an off road lift truck since they are rated for 1280 pounds each. They require no air pressure. I did not remove the axle and bearings on the front wheel. I plan to use them as is since they are still running smoothly. I did have to remove the rear axle since it was bent.