We changed the jets from the 50hp setting to the 75hp setting and let the truck run on the rollers. The first dyno run with the 75 shot resulted in a peak power number of 675 rwhp. We noticed, however, that the curves, as was the case with the 50 shot, showed the engine's need for more timing. We raised the timing from 9 degrees to 10 and then let the ponies run once more. The result was an increase of 8 rwhp over the first 75 shot dyno pull, and the overall numbers increased to 683.27 rwhp and 770.51 rwtq.