Putting a 400 series in my 560 right now. If you want to do it economically, it can be done with stock parts. The rear plate bolt pattern is the same as the later tractors, all the way through the 86 series, so you can use the factory rear plate to bolt it to the 560 clutch housing. '06-'56 series frame rails are almost 3" longer, and should be enough for a row crop tractor. Mine's a wheatland, so the front bolster hangs back under the engine for the setback front axle- had to stretch the wheelbase about 6". Easiest would be to use 66 series frame rails, but it won't look stock, and the front bolster won't fit as well. My motor is N/A, so not too worried about rearend strength. I've been told the front of the fuel tank has to be removed to clear the valve cover, but that's not true. I bolted things together last night, and the valve cover even clears the heat shield under the tank, but not by much. Tank will have to be removed to adjust the valves. The stock tractor front plate can be used, but if you're using 560 or '06-'56 series rails, the mounting ears will have to be narrowed about an inch per side, and the bottom inch or so of the ears will have to be cut off to fit in the rails. Only the top mount bolt can be used (one bolt per side). That gets things bolted up, but the flywheel issues have to be addressed. If you need steel, just order a custom flywheel ($$). The factory 400 series tractor flywheel can be used, but it has to be machined to fit the 560 ring gear, and spaced back 7/8" with a spacer between the crank and flywheel. I got my spacer from Floyd Isbell in PA (Isbell custom tractor parts). That gets ring gear mated with the starter. I've been told that the stock 560 flywheel can be re-drilled to fit, but don't know the details. Now for the problem: As I was bolting things together last night, rotating the engine to make the clutch splines line up, I noticed the clutch shaft was not engaged with the clutch disk, and was only 1/2" from being pulled together. It seems the disk/pressure plate is sunk too far into the flywheel to properly engage the clutch shaft and pto drive splines. I just spent $325 in machine work on this flywheel, so I hope I can solve this. Possibly a longer clutch shaft. This is not an uncommon swap, so I'm not sure what went wrong. I used the flywheel that came on my 414, out of a 966. I also have a combine 414 flywheel, but it's thinner, and would require a thicker spacer, but it appears it would put the clutch in the proper place after machining. I'll know more today- gonna bolt the engine to the clutch housing without the clutch, and see where the clutch shaft is positioned relative to the flywheel. I'll post with the results. By the way, I used a 986 clutch, same dimensions as 560, but supposed to have stronger springs, since a 986 has a hydraulic assisted clutch.