I've had a similiar problem as you mentioned earlier. I solved my looking at the rpm of the water pump pulley and upgrading to US Radiators desert cooler series of radiator. The desert cooler unit are triple flow units that have baffles to slow the coolant down and ensure the most heat transfer is occuring. Granted these radiators aren't the hi-tech aluminum that everyone expects to see. To me, The look is secondary to watching a temp. gauge climb to the stratosphere. Another tidbit - Use Spal fans. I'm running a 2600cfm pusher unit as a back-up to a Mopar heavy duty fan package. Good luck.