Radiators: Is 22" enough for 400 HP?

I've got a Champion 3 row in my Dart with a big block, 400+ hp, and it cools just fine on 90* days with no shroud. It was inexpensive, well made, and fits well.

One reason I didn't go with the 26" was because of all the cutting necessary to the radiator support in order to let the extra 4 inches of radiator see any airflow.