I have tried multiple times to set my timing according the factory manual but the factory settings never provide the best results. To achieve the best results you need to have the pump timed repeatedly while running multiple dyno runs. With the help of a dyno you will know exactly what's going on with your engine. The first time I had my local diesel shop time it off of the dyno I immediately noticed more power and achieved 10mpg better fuel mileage. According to the dyno I am now making 115hp instead of 84hp. It's worth the money in fuel savings alone in my opinion.