1990 Mazda Miata Steering woes

Steering problem
1990 Mazda Miata V8 Two Wheel Drive Manual 0

I have a 1990 Miata which I implanted a 289 Hi-Po from a 1966 Mustang. The engine has a lot of goodies along with a March Performance pulley kit #30168 with a side mounted A/C and a Power steering pump from a 71 Impala.I connected the hoses to the pump and when I start the car up it sounds great, but when I steer the wheel it shakes violently and I have yet to drive the car.I was thinking that the pressure may be too much from the power steering pump but I am not sure. My question is how and or what do I need to do to remedy this problem.