Aluminum rad?

[85_prairieboy]

I have been having overheating problems with my truck. It only overheats on warm days when idling but nothing is worse than being stuck in traffic and watching the temperature climb. Popping it into neutral and revving it up helps somewhat but I know I have to do something different. The engine is a 10.5:1 350 with AFR 195 Eliminator heads and an aggressive cam making 425-450 hp. The last time I built my engine I used a Weiand high flow water pump and installed a Flexalite electric dual fan setup on the rad. There was a small improvement. The rad is still the factory small core rad but I initially thought the dual fans should be able to keep up with the heat compared to the old belt driven flex fan. My question is what rad do you guys prefer? Should I spend the big bucks on a nice aluminum rad or find an oem rad that would have cooled a big block? Or am I overlooking something?