Straight lift requires less figuring. For cylinders force = area time pressure.
example: 4 " bore cylinder has 12.5 square in area times 1000 PSI = 12,566 lbs of force or at 2000 PSI you have 25,133 lbs of force. Figure a yard of wet dirt is 2500 - 3000 lbs you can in theory lift 8 + yards. If your pivot point is at the opposite end of a 6 foot trailer with the load even distributed you could in theory haul 16 + yards.
Never use max system pressure to figure cylinder forces unless you are using a single acting cylinder or moving very slowly. There will ALWAYS be line losses on tractors. Generic rule of thumb I use 85 - 90 % of max pressure should give you a close estimate on the actual force you will be able to achieve while the cylinder is moving at a reasonable speed.