I am running a 261 in my '50. I found that I couldn't get a fan to fit to my satisfaction, so I used a 2400 CFM electric 17" on the street side of the radiator. I am running a short waterpump with a Ford pulley. I am running a GM 10si alternator instead of a generator, though. The fan draws 15 amps. I have a thermostat on it so it only kicks in when the radiator gets hot. It works in 100 degree weather just fine.
The alternate way is to get the adaptor plate that lets you use the old 216 water pump. It moves the mounting point up high on the block and lets you use a mechanical fan. A friend of mine has that setup and it is what I would use if I did it again.
