18” or 18.5” fan for a 440?

Putting a 440 in my 69’ Dart.

Would a 2863216 7 blade 18.5” clutch fan cool better than a 18” 7 blade clutch fan?
Or is the 18.5” fan not compatible with this car at all?
I know the 216 18.5” fan is not listed for the 69’ Dart for some reason. Would there be an interference issue of some sort with the larger fan?
Thanks.