Has the 436 diesel in it, they are 161 hp., have self adjusting, wet hydraulic-powered brakes, muffler is under the hood, has an improved TA over the 66 series IH, also the operators cab, if so equipped, showed a big improvement over the 66 series. Had two 12 volt batteries compared to the 6 volt batteries in the 66 series. The most popular tractor of the 86 series was the 1086, IH sold over 50,000 of them. I think all the 86 series were fitted with the water filter which helped with the cavitation problems that were seen in some high houred wet sleeved 400 series engines.