I have a cheap aftermarket afco aluminum and it works well for me. Stock appearing or stock fitting does not concern me so I made it work. That being said, I thought brass cools better than aluminum? All the higher performance small cooling products I see are copper or brass/bronze. If you have a recored 3-row oem rad I would be looking elsewhere for the problem before replacing it.

Firstly, if you're running a 160 stat and if everything is cooling well your max temp should be holding at only 5 or so degrees above thermostat temp. Personally I think 180 is a better temp for a driver but that's a separate discussion and nothing to do with your overheating issue. Secondly, your initial timing is too low, I would bump that up to 15° because too little timing can cause overheating problems as well. Too lean can also cause overheating but typically you would see that problem at cruise, not idle. I would be looking at whether the water pump is not pushing enough, pump speed too low or bad clutch fan not locking enough to pull full air at low engine speeds. How is your fan sitting in the shroud? I think the fan blades are supposed to be sitting about 1/2 way into the shroud.