Looking into replacing the heavy duty thermal clutch on an RV 413 with one that can be switched.
The factory fan pulls up to 5,500 CFM through a 24" radiator, and I have not seen an electric combo that comes close.
That said, bigger trucks almost all run them: https://www.summitracing.com/parts/hda-3330
The trick is finding one that will bolt to the 4 screw pump with its 5/8" nose, or can be reasonably machined to fit.
Most also use the newer style fan that bolts to the perimeter of the clutch, which is fine.

Any truck radiator mechanics have ideas?