Well if everyone ran under the theory that the German engineers did it best, we'd all still be driving bone stock splits with 36hp. I, on the other hand, am quite happy with the suspension, engine, interior, safety and other improvements I've made over the engineers in '71.
But to each his own.
I do agree, however, that at high RPM's the stock fan has to be cavitating like made, fortunately I was only spiking the RPMS to those levels (most of the time). But regular driving on the old high-revving motor meant cruising at 5500-6500 rpm, which means a stock fan belt setup is slipping so much you cook belts in short order. Who knows what kind of airflow the heads were getting?!
-Dave