440 HP manifolds vs. headers

I am sure that this has been done before and I am sorry, but I have located a set of HP manifolds from a cop car with a 440 sitting in a classic car junk yard. How would these fit in an a body and how do they compare flow wise to TTI's or Schumachers? I want to build a good street strip 440. How much are these worth with no cracks?

what year cop car , the later 70's car had manifolds that LOOKED like HP manifolds but were not .

As far as a comparision from a real HP manifold to a set of TTi or even the schumacher header , there isn't one , the headers win hands down .