Ford 5000 hydraulic pressure relieg

[rainycanyon]

Is there a way to adhust hydraulic pressue (lift arm lift ability) i want to be able to lift 5000 lbs @ the pins

 

[rainycanyon]

It has a class ii 3 point which should lift 5000 lbs but i can not find any conformation

I plan on hitting it at 4500 lbs