Well I read the article and as it was much more about the history of the #22 car and its last race there was little on the 305 build.
Point of contention was that they decided to use w-2 heads however to the best of my knowledge the W2 was not yet invented and it was not what Keith Black used. In fact Hot Rod did a piece way back in the 70' on this very Keith Black Combination and the photographs clearly show standard 340 "O" heads. So not sure whats up with this and I would have expected MCG to catch the W2 issue.