Ok so now I know what they are, but are they any good or would you try to find something different?
It really depends on what you are trying to do, but they came from the factory with 2.06" and 1.72" valves. If you are putting them on a flat top engine they will boost the compression up by a couple of points, but they could really stand to have the larger 2.19" and 1.88" valves installed and bowl work, if putting them on a 427 or larger engine. The normal consensus is that the open chamber heads work better with flame travel and combustion, but I have run 9.50's with closed chamber rectangular ports on a 468.