ps pump question

I just replaced my ps gear box with the durango box. Works great, but im still having some issues with turning. When i try to turn with out my foot on the gas, it is hard to turn. Would this be the pump going out? I thought it was the gear box because it was leaking like a sive, but now the box in new and it is still hard to turn not under power? Any thoughts?? THANKS!!

my guess is the durango box needs more volume to operate correctly. the stock pump isnt pushing enough volume at idle speeds to operate the larger than stock box.

edit: this is mod tech

i put one from a 4.0 HO in my 2.5 xj to the same results...haven't bothered to look yet, but i think i'll largen the passageways