The 2155 was produced in the early 70s and at that time was the most powerful 2WD that Oliver built. The tractor also could be gotten in a LP version. Yours is probably a 71 model. The est. HP is 156(wasn&#039;t tested at Nebraska) with a weight of 12,420 lbs. According to serial numbers there were few of these tractors built. (ser43300043-4333000253) This tractor was also produced as the MM G-1350.