Indeed. It would help if the shop could share dyno results from some kind of known combo that might even have a time slip behind it. Something to ground the results.
Lots of "500 ft lb" builds are bogus, and make it seem like an easy task. It may not be hard, but ported iron with a questionable intake make it more of an uphill climb.
Lots of professional porters have shared that flow can be deceptive. Lots of ways to get "excellent" flow from iron while making bupkis for power. So there's that too. Flow at .600 isn't the whole story, and cfm isn't the whole story either..