Rocker arm recommendations?

Anyone know approximate cost on the B3 rocker offset spacers having trouble with geometry on Promax 171 heads have tried Crane & Harland sharp Rockers ordered a set of Hughes which I use I most builds see how they line up.
Also had to take a heap of the intake side of the head inlet manifold side would not fit I know it fits the factory edelbrock RPM heads also some air gap manifolds same problem on the promax heads but not on the factory Edelbrock RPM's