I wouldn't focus on wattage alone. A crappy inefficient fan could easily pull tons of juice while doing nothing.
One thing I would like to revisit myself is a later model Corvette or Camaro PWM fan or the later model truck PWM dual fan setup and the dumbo ear shaped air guides that bolt to the condenser and catch airflow from the full width of my grille opening, forcing it through the cooling stack while blocking it from going through the openings behind the headlights as well as a longer air dam.
The Express has lived long enough that at some point GM decided that airflow management through the cooling stack was a good thing and created these air guides that bolt to the condenser mounting bolts and help direct the ram airflow from moving down the road through the gille opening through the condenser and radiator while blocking airflow out of the engine compartment that would otherwise take away from airflow the lower pressure area created by the air dam creates.
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