They may not make them anymore, but there are still places selling them new.
It's pretty tough to find the intake seals these days and the intake manifolds are getting a little rare.
I recently had to send one out for repair because I could not find a replacement.
Overall, I kind'a like the heads.
I have a 1995 89" stroker with HD heads ported to match an Edelbrock manifold.
I had to remove the rear head and I reused the manifold gaskets.
I haven't had any leakage problems.