I couldn't imagine an 8' offset being all a 15,000 pound tractor wants. What size are the disc pans? I pull a 9' offset disc with 26" pans that weighs 3k give or take a few pounds with a 93 hp JD 4x4 tractor that with loaded tires and FEL probably only weighs in at 10k.Offset disc. Takes a lot more tractor for that one. Our big tractor weighs 15,000# and an 8' offset is all it wants. If it was 8' 1", probably wouldn't pull it.
Ours is an International pull type with hydraulic wheels to lift it. Maybe your dirt is different. I do know that offset discs will tear the world up. Lot of times we just break the garden with it because it cuts so good. Then we have a large butane tank we made a packer out of, pull that over it and lay the rows out with a Covington planter on a cultivator. We learned to use that packer because if it rains, garden won't be near as boggy.I couldn't imagine an 8' offset being all a 15,000 pound tractor wants. What size are the disc pans? I pull a 9' offset disc with 26" pans that weighs 3k give or take a few pounds with a 93 hp JD 4x4 tractor that with loaded tires and FEL probably only weighs in at 10k.