Did the stock big block cars overheat? I don't think they even had shrouds on them. If you use a good radiator and a belt driven fan with a shroud you should be okay. If you are hot rodding the car then you might need to widen the core support and go with a bigger radiator from a B body or C body. For a street car you want to use a belt driven water pump with a big engine driven clutch fan. Hooking up a modern coolant recovery bottle is also a good idea.
