Two back-to-back pulls were made with the Edelbrcok heads, and, as this dyno sheet shows, horsepower was up to 556-an increase of 13 hp over the best the steel heads could do. Even more interesting was the fact that the horsepower didn't drop off as suddenly as it had with the steel heads. Also noteworthy was the fact that while peak torque only increased by 4 lb-ft, the torque curve was substantially broader than with the steel heads and at a higher rpm. This means more usable power at the track and more consistency with shift points being less critical. Backing up our dyno numbers was the fact that the pull time was reduced by one-tenth of a second, which means the engine accelerated quicker, a function of the additional torque and horsepower.