Good thing you bought the car Daniel. I had a tax refund burning a hole in me pocket.

There are several different fans for different applications ranging from a 17.5" 4 blade, to a 19.5" 7 blade clutch fan. Where is the fan hitting the shroud? Does the radiator have clips at the bottom for the shroud? Correct radiator?

Is the fan shroud you have for Firebirds? 'Bird motors are offset to the passenger side to accommodate the steering gear. So the fan opening will be offset in the shroud as well.

Sorry about all the questions, but I think the fan size isn't the problem. Having the correct shroud and it being attached correctly are more important.