67 Barracuda Heavy Electric Load

Which is great if the engine can run without a fan, he can save around 31 horsepower at 5100 rpm over a fixed mechanical fan which he was never considering.
But to be really fair, I did not see an alternator on the front of that 350. So with an electric fan, unless he kills the fan or the alternator during the 1/4 mile run, there's drag from the alternator's magnetic field.
So its not 40 hp, its not even 30 hp over a big fixed blade fan. He was asking about a clutch or thermal clutch fan which he already owns.

What Dallas is asking about is why there is a problem with his "charging" system.
So there are two reasons why the electric fan is relevant to his question.
1. Depending on how it was wired, it may be confusing the ammeter readings.
2. Depending on how it was wired and how much power it draws, it may be overloading a circuit, or the capacity of the alternator at low rpm.

As he is not that familiar with electrical, and we are not there, switching to the factory fan is likely simpler and will cause less damage than reworking the original wiring strategy to accomodate this fan. And even if that was all done, from the photo I would not bet that the fan and shroud will be effective on long distance drives in the summer.