From one of our customers:
This weekend we were chasing a power problem; considering the torque converter change; adjusting the launch RPM; after all of that to no avail, we found a plugged nozzle jet; the header said so; it was discolored in that cylinder only, after the previous run, from overheating.? The plugged nozzle jet was cleaned and reinstalled.? The performance immediately picked back up.

More knowledge from all sources, including technical books such as ours, help to sort out problems such as this.? They are simple to fix, when you find them.? Finding them can be a mystery without specialized knowledge and experience.