Fan to Radiator Clearance

[64.5 TX Stang]

What is the proper clearance between the fan blade and the radiator. Mine is currently about 1.5 inches, but I feel this might be too much. Any input is greatly appreciated. BTW I have a 64.5 mustang with a 65 200 six. Thanks!

 

[MandarinaRacing]

Most aftermarket fan retailers recommend exactly that 1.5 inches, any closer and....well you get the idea

Alex