I stand corrected!
Link to shrouding article
If this fella can drop his CPU temp from 51.8 to 44, You might as well give it a shot.
If you want a quick idea of how beneficial it can be, try ducting with tape first.
As for the fan, it will deadhead at .25 inch pressure drop. In other words, the actual flow you are getting is probably closer to 75 cfm (max 125) with a pressure drop closer to 1/16 inch.
Specs here
You might consider a more powefull fan, or multiple fans.