"I have 3 Massey Ferguson 399's. A 1988, 1989, and a 1992. The newer tractor has 5 more horse power, and the engine is easier to work on. The older tractors have 90 PTO horse power and tractors after 1990 have 95 hp. I am very large, and my size 15 feet have trouble with the clutch and brake. The clutch as two positions for adjustment, so I had the brake pedals cut and welded so they are similar to a Farmall M. I also had a plate built to raise and move the seat back about 2 inches. I put up hay on 7 farms in the West Virginia hills. The MF 399's have enough power to go up hill and down without changing the throttle, pulling a 4x5 baler or 10 ft discbine. The diesel engines don't have a computer or turbo so they present very few problems. They have 12 gears forward and 4 reverse accomplished by 3 levers, a standard 3 speed syncromesh shift, a syncromesh 2 speed shift, and a high-low range lever that requires the tractor to be stopped for shifting. No power shifting. The range of speeds is good for farming, but the shift between 6 and 7 gears use of the range lever. These are the gears I use most frequently. The Perkins diesels have good fuel economy. Of course, they use more than the smaller MF tractor I use for raking. The tractors are a bit light and need suitcase weights on front and loaded tires. The '92 model has 18.4 x 38 tires and has much better traction than the tractors with 34 inch tires. They have been trouble free for old tractors. I really like them."