Re: BB Cooling Fan
My suggestion is find a seven blade thermostatically controlled fan off of either a mid seventies to early eighties 400 SBC or 454 BBC pick up truck. Takes much less horse power to keep engine cool.
Also recommend a BBC fan shroud (get it from the bone yard with the fan) and as soon as you can afford it either a Griffin or BeCool aluminum radiator. It is no fun to have to push your BBC car with SBC cooling through traffic lanes at drive ups because it will overheat at idle.
I had a 427 L-88 no A/C with a 4 core brass radiator, SBC shroud and a flex fan that would boil to the ground after idling for about five minutes. Learned to save embarrassing myself by walking into the bank rather than try the drive through lanes.
Larger Dave (from sunny, hot, oppressively humid, Florida)