That's the way I set my timing, somebody installed a cam don't know what size. They put a carb. on it with doing anything to it. I had to change the jets to a smaller size, reset timing to around 16-17, Car ran a whole lot better, not a race car or anything just pleasure to drive. Didn't do to much with the dissy, will have to recheck, it's been a number of years now when all that was done.