Exhaust manifold helP!!

I am just about ready to put my 360 in 66 cuda but just need to know exactly what manifolds i should use. I have a set of magnum manifolds that i picked up cheap but i dont think they are going to fit. I have found a set of 318 manifolds from an a body should i just pick them up and be done with it. I have a power steering car so i am really worried about this. Also can i use the saginaw ps pump that is on my 360 in the cuda thanks