Radiator

Whats best for limited street use? Aluminum or Std Brass? Any other ideas on keeping temps down on street?

It sounds like you're asking "what is the best radiator to put in my race car that may be on the street once in a while?". Aluminum is the best choice due to the weight benefits. All radiators need a shrouded fan(s) across the entire tube area, and they need a low pressure area to flow to. Factory cars have a small chin spoiler under the radiator to create this low pressure area (NOT to be confused with the front aero spoiler). A flow restrictor or thermostat is required. Proper water pump speed is required. 50/50 coolant is the best choice, water won't get it. That should get you started.

a must is an electric fan if you dont already have one.

i have a fluidyne in my mustang, it works GREAT. its amazing. 300 dollars, its fully tig welded, aluminum, 3 core. we *TEST* drove it without the fan and it ran around 200 degrees cruising. works great. rins about 175 with the fans. its amazing.