after talking to a rad guy he steered me away from aluminum rads and got me into a re-core using a high efficiency core. aluminum doesn't transfer heat well like copper or iron. It is super-light which is why the after market loves them. for shear cooling, transfer of heat, copper is much better.
the effects are amazing. Standard 3 row core aftermarket rad kept my temp gauge high in traffic, this was with a 7 blade fan and shroud
after i switched to an original case which fit a 2 row with a high efficiency core my gauge rarely went above half, again same blade, but i changed the shroud to a ford OEM to fit the original rad.
then later i added a shroud extension piece that originally came with A/C cars and my gauge dropped down from a 1/8 to a 1/4 even when it was 97+ degrees out.
that was a shocker to me, that a little 2" by 30" piece of plastic could make that much of a difference but it did.