Need some more history, what do you mean, "looks" to be new? Has the power steering ever worked in this car? Is this the first time the car was ever started with new P/S components? Are there any kinks in the hoses? If everything is as it should be, and you have nothing going on at all, I'd say your pump is probably bad, but it could be the gearbox also. Is it making any noises at all? On a big block car, assuming you have the correct P/S reservoir, it's pretty easy to get another pump and replace it. I got one from O'Reillys and transferred it into the old reservoir, cost about 50 bucks.