Mauser is right.

SLR_dave, the 12 port head with the blue motor introduction might have been responsible for the noise you spoke of but also the fan did get noisy when the viscous coupling (basically a small chamber with temperature sensitive expanding wax pellets in it that when they sensed enough localised heat they swelled enough to "engage" the fan) cut in.

The large shroud was std on a/c vehicles along with factory tinted Pilkington glass and a couple of other things like front springs (to take the extra weight of the full a/c unit ) etc. A good viscous fan and shroud set up works really well. I've kept mine in case I ever want to put it back standard. The couplings are still available new and you can test them by noting them 'cycle' when the unit temp reaches around 90-95 degrees C. Check it with one of tje cheap laser temp sensors while the engine is running.