which fan

I tried a flex-type fan on my little 366, with a 26" A/C,shouded rad(extracted from a 73 Dart). It didnt like it.I also tried several different small diameter 5 to 7blade fans,on viscous clutches. Only the 7 blade fan,directly driven worked.
What also did work was a FORD thermostatic clutch and an OEM Mopar 7 blade steel fan, with the heavily curled tips.Since it worked right off, I didnt try anything else. I run 200ish *F at the stat house,full-time. Always have. Its rock steady.