In my opinion a 2 row is just not enough cooling surface for a mild build V8. It may be overkill but I put a 4 row aluminum in my fairly stock '48 Burb w/350 V8. Close to the same price as a 2 row and I have the extra cooling I need. Heed the advice about the fan shroud. It does help.
The thinking that you need more than 2 cores is from the old copper-brass radiators. Most aluminum rads are 2 core, but 1" to 1-1/2" tubes, so they're much different than a typical 2-core. My rad in my '46 is a 2-core with 1-1/4" tubes, and it cools my 455 just fine.
The truck is a 47 (2nd series) that I am moving over to an s10 frame. As far as traffic, the only sitting in traffic would be trying to get into.show type of stuff. Heat and humidity.... July/Aug usually tops out around 100 humidity I really can't tell as I try not to say attention to the number.... looking at a 2 core....
Usual is still in the mock up stages, I am trying to decide if I want to stick with the stock style but the alum version or change things over to a cross flow (already have a 2 core that is about 31w20h).....
I remember as a kid ridding with dad in his big block powered 41 coupe he would always complain when we had to sit in traffic for extended time cuz it you start to warn up that was with out a/c..... I just don't really want to fight that when I get this one finished....
Don't buy a rad until you get your truck mounted on the S-10 frame. Depending on where it ends up, the stock replacement rad may or may not fit. You'll be best with a downflow, not sure why you would want to change to a cross-flow.
