I have a 1991 z28 w/ a 350, and when I bought the car it had an underdrive pulley on the crank. The power steering always goes away once I approach an idle (usually 1000 rpm's (worse when the car gets hot- 1300 rpms)) and so I have to rev the car to take corners or to park etc. I always thought it was the underdrive pulley, so I just dealt with it. I just replaced the pulley and belt with a stock one and the problem persists . is it the pump? if so what kind should I replace it with. I would like to run the underdrive still so do I need a better or different pump?
Thanks: