My dyno's with a Needswings single and Code3 pulley were under 300 hp. It wasn't until I got a tune that I broke that barrier. It's easy to say don't worry about the low numbers and I'll say the same, even though I had doubts when mine were low compared to what others were reporting. Having spent lots of time on a dyno I'll echo what's already been said, dyno's are principally for tuning and measuring the effectiveness of changes ....... and dyno days to make extra profits. My best Mustang dyno was in my sig, dragtimes calculator says between 380 and 385 at the crank for me. You know your car is fast and making safe power. That's all that's important.

Les