For the races I plan on running ad ADA head. But I'm cheap and don't want to spend the extra cash on higher octane fuel when I'm just playing around. But the bottom end on the ski is great and the hookup is great. It beats my brothers 62t/61x with 44s, red pipe, msd, with a concord 13/17 out of the hole for the first 100-150 ft but it's a couple MPH slower on the top