[RocktimusPryme]

That’s somewhat common on electric fan conversions. Though you see it more with dual fan setups. Because there is too much surface area blocked behind the radiator to allow airflow through at highway speeds.

By all means check timing and stuff as others have said. I wouldn’t think from the look of that shroud it would be super restrictive but if all else fails you might place some shroud vent flaps in each of the corners.

I might also try it without the OEM shroud too just to rule it out.