Matt I'm using the 3 row GX radiator as well , it always ran cool. I was bad and the car was out of my care when I had the sports racer AND it's been in there since 92 it needs a good cleaning , I've flushed it but it's time.

I too like the SU's as they are versitile , plus I often throw a student in the passenger seat so the extra weight means the motor is sometimes lugging down around 3500 RPM's coming off corners, which the SU's are fine with.

Tom