i had a double disc plow on my D-14.
it worked great, heavy old plow.
I assume its a snap couple hitch plow.
be sure the adjustments are loose so you can make the necessary adjustments.
adjust the top link so the frame of the plow is level front to back arm adjustments so the plow is level side to side.
the tail wheel must be adjusted so the plow follows the tractor. You just use trail and error until to get the plow to follow straight behind the tractor. as you move the tail wheel adjustment the plow with move to the right or left as you adjust. You just have to keep working with the adjustment until you get it to follow you.
mine did not need tailwheel adjustment it followed the tractor great.