^that's a dynapack dyno, which is load-based, not inertia-based like a dynojet. Also, the dyno bolts directly to the car's hubs, so there is no wheel weight to spin. So this particular dyno reads higher than a dynojet by about 15-20hp from what I've seen. Mustang dynos read much lower, but it really doesn't matter AS LONG as you use the same dyno for the before and after pulls. you are looking for the delta between the tune, not the overall number. The dyno owner said that my "after" pulls were right in line with what he's seen 330i's make in his shop, so I was happy with that.
Looks like they stopped your dyno at around 6500rpm? You might of made more power if they ran it to 7000, but it's hard to speculate exactly... and for a mustang dyno, those are decent numbers.