I've got RDZs on a 421 Cub, and Shearers on a 392 Cub. I love both of them. Can't compare the 2 on those different motors b/c they (the motors) rev and pull completely different.
Buy the ones you can find the best deal on. I bought the RDZs new, bare for $550(?), and you can find chrome, used RDZs, CPIs, Shearers, all day long in the $400s.
200 psi? Isn't that a little much for a drag racing engine? I like 180 psi, some guys even like 160 psi.