I've added a truck snow plow to my JD. I took a 24" TSC cylinder, my table saw and a metal cutting wheel and produced a shorter cylinder for up/down action. I took it apart by removing the cylinder tube and cutting it down. Then I cut and rethreaded the 4 tierods that hold the caps together. Finally I chopped off the end of the rod to the length needed, ground a flat, and cross drilled a hole for a pin. It is very easy to pull the cylinder apart and put it back together. The saw gives a nice square, smooth and burr-free cut.
Problem solved. By using a direct 2 way cylinder, I get the downforce occasionally necessary to scrape through ice and slush.
BTW: I made use of the 2 original one-way cylinders which swing the blade for left or right discharge. The original rating was probably 1200 - 1500 psi from a truck 12v pump. By using very small ID hoses, I get by with by 2500 psi tractor loader circuits just fine. It certainly swings fast! (Enough to actually throw snow out the side if necessary).