abell,
Not sure about TX in the summer, but up here in Washington State I had no problems with a recored original radiator with a healthy small block in the original location. Changed the water outlet / thermostat cover to one that stuck straight up instead of at an angle and clearance from fan to radiator was plenty as the 8 is shorter than the 6. I did make a shroud to make sure as much air was pulled through as possible and I used a flex fan on a spacer to get it close to the radiator.
When it was in the mid 90's outside and I was in traffic, the temp would climb up to 200 (normally around 185) and stay there. I turned on the heater and rolled down the windows when it did this . . . my girlfriend didn't like it, but considering how much work and cash I had tied up in the motor . . . well, I had my priorities straight!
