3 Blade Clutch Fan Question

[trucknut85]

When i got my 85 Chevy K10 it had a 305ci engine with a 3 blade clucth fan. But when i swapped out the 305 to a 350 i went with a 6 blade flex fan from the auto store cause i was young and it was shiny and cool. I'm now trying to restore my truck back to more of a stock look. I'm curious if the 3 blade fan was stock on a 305 at the time, or was it a replacement as i'm not seeing a replacement 3 blade fan on any of the major 73-87 parts sites. Should i just upgrade to a 5 or 6 blade clutch fan? Any input would be appreciated.