The parts book actually calls for a 5 blade (18.5" dia) part# B7Q8600C. The parts book shows ONLY 5 blade fans for all trucks 1948-56, so I wonder if the 4 blade was supposed to be on the passenger cars.
38 Coupe, I see you changed the pic you posted, where was that one from, as it indicated the fan part # to be 8602?
Anyhow, Part #B7Q8600c
Dennis Carpenter has 2 NOS
Klimesh Motor Sales Calmar, IA 52132 has 2
Miller Obsolete Binghamton, NY has 1 $90.00
1950 F5 Stake Truck Flathead 8 "Edith"
1951 F1 5 Star Extra (in progress) "Dollie"
2001 F250 XLT V-10 4X4