I need to replace the fan and cowling on my SA, because the motor howls like an old Aquavac and the top strut of the cowl that holds the motor has fractured

I don't want to take it out to just repair the cowl when I know the motor is shot.
Does anyone know if it's possible to fit the 500W 350mm TD fan and cowling to a petrol rad, to replace the 450W 305mm fan?
Will it clear the tunnel etc? Were they steel or plastic?
Sneaky wanted: anyone got a TD cowl? Steel one preferred.
1985 Oettinger 3.2 Caravelle RHD syncro twin slider. SA Microbus bumpers, duplex winch system, ARC 7X15 period alloys