Need a better radiator.

I have the same problem in my '73 318. New 26" stock style radiator with factory shroud & clutch fan. Works perfectly 97.62% (approx.) of the time. Was driving in 105* heat on the freeway & got a little too hot to be comfortable with. It was the only time I've ever seen it heat up that much. That said, I still want a radiator that can handle anything thrown at it. Iv'e looked at the thread about the Champion radiators & the pricing looks good...