Patric, are you running the ram assist yet? If you are not then I can't see why you are having such a problem unless there is a big air pocket in the system. This is pretty easy so try this first.
Jack up the front end and put it on jack stands.
With the truck off, unhook the return line at the pump and hold it in the resivore hole on the pump.
Have somebody in the driver seat just turning the steering wheel back and forth from lock to lock.
Do that for about 5 minutes and then hook the hose back up and top the fluid if needed.
After that see how it does. You can also try changing the fluid. If that does not work then you can try a remote resivore to help but I can't see why with just crossover steering you are having a problem. /forums/images/graemlins/dunno.gif