From what I've seen over the years only about 5% of the customers are actually interested in finding more power after a dyno session. Most customers just want to get the engine home so they can put it in the car and get back to racing.
Did the owner at least have a few ignition timing settings tested?
The combination 4150 intake with carb adapter to 4500 may have limited top rpm power capability at 540 CID.
It would be interesting to see how the HP held up past peak. It might benefit from a higher shift point.
