1936 Fan dimensions needed!

[Bruce in southern OH]

Reinstalling a metal 4 blade fan on a 1936 car, (had a 6V electric fan, pull type ) the fan I came up with when installed on the front of generator is to close to the radiator hoses. ( like a gap of only a 1/8" ) Need to know what is the correct length of hup/spool portion of the fan. I looked at search section of early V8 forum but did not come up with an answer, lot of info but not exact, thanks Bruce