[HoosierDaddy]

I did a little research before modifying the cooling system on my '78 Newell. The issue is noise suppression. The more turns the cooling air makes going in and coming out the less engine noise that is able to escape the "box".
The squirrel cage fan helps in three respects. It allows for a lot more air movement with less noise than a typical engine fan, eliminates a direct path through to the box, and by "packing cool air into the box some of the surface heat of the engine is exhausted throught the radiator and out the bottom.
I was able to dramatically reduce the gen noise outside of my '78 by adding metal-work around the perimeter of the radiator to seal it to the front of the box, then I closed off the traditional grill and modified the front cover so that it drew air in from below the front bumper instead of directly in the front.