SPAZZ,
Did you remove the stock electric fan and replace with a 12" or are you manually switching the stock fan? Or, did you replace the stock clutch fan with a 12" electric as a 'Puller'?
My efforts for a thick radiator have hit some bumps. The builder split with the deposit. His brother, with a real radiator shop, has sent a stock unit as a model to a custom shop in Az. If it comes to pass, it will have a 2600 cfm puller fan in place of the stock clutch fan. Still waiting.
Roy