Volvo did; but only on the non airco cars, all the others have electric fans. I don't think there is any real point in supplementing that with a mechanical fan. The non airco cars also use a smaller radiator, the same in fact as a 240.

Sooner or later the car will need a headgasket. It's easy enough to change, not particularly expensive. It isn't really a function of the fan it has, it is the inevitable result of slight movement between a differently expanding aluminium head and casr iron block. I generaly reckon on 150K miles, but I've seen gaskets go on for way longer.

Using good quality anti freeze and changing it every few years will do more good than the mechanical fan I reckon.