Tom's dyno testing clearly shows that the lumps improved HP and Torque on every combo compared to the same head without the lumps throughout the same RPM range. This is data that didn't exist in writing when Leo's book was written, so he was probably basing his thoughts more on conjecture than proof that was available at the time or just didn't want to give credit to something he couldn't give solid proof to. Sissell and Kirby's data has always shown the lumps to be beneficial in all RPM ranges, and Tom's findings just further shows that to be true.
