[FWB]

i would send it back and talk to KC racing for a cam that will play nice with your build. if you already have a certain valve spring on your heads you will have to stay within those constraints or redo the heads with springs compatible for the cam chosen. lots of variables to consider depending on what is in the motor, heads, springs, rockers etc, an easy decision to use X,Y, or Z type of cam is not able to be made without a good evaluation of the components you already have.