Vintage Cars: Electric fan for 72 450SL, mercedes 450sl, flow rate range

Question
Hello Ron: Hope you can help.

I would like to replace my pulley driven cooling radiator fan in my 450SL with an electric fan.
How large (CFM rating) electric cooling fan would be needed to meet the cooling requirements of the V8 4.5L in my Mercedes 450SL ?

What is the CFM flow rate range that is generated by the pulley/clutch operated fan used in the 450SL ?

Thanks, Frank

Answer
Frank
Well I have every available manual for the 72 450 including the shop manuals and this data is no where to  be found.  You may try MB classic center , they might be able to help.
I do know you will have to pull a great deal of air as these cars are designed to run hot, and will overheat easily if not properly cooled. Why the change?
I would assume it would need to run full time ( unlike the AC fan) and may be noisier than the actual fan
Good Luck
Happy Motoring
Ron