I read an article in engine masters one time and the very successful small block builder was talking about the success of the w2 and its progression to the Indy 360-1s and he said it was not the peak flow numbers that made the w2 great, but it's low lift flow numbers that were impressive and the optimum port size that generated very good port velocity(torque) at low lifts. Ryan at Shady dell recently explained to me that the w2 in a max effort makes more horsepower than its flow numbers would indicate in comparison to other more modern heads.