Remote Trans Cooler

[67chevysupercharged]

Ok wasn't sure if I should post here or in the engine & drivetrain section but think this might be better here. I am currently building a 67 with 6.0 & 4L80e swap and ordered a transmission cooler for the truck. The truck will eventually get a decent sized cam and aftermarket converter and wanted to make sure I bought a cooler that would keep the trans cool enough for primarily street use and light track use.

This is what I ordered for a standalone cooler.
http://www.summitracing.com/parts/der-13950

When I called Derale though, the tech guy said I should order this cooler if I wanted to run the cooler as a standalone because he said the 13950 would have to be run with the radiator trans cooler to keep the trans cool enough especially with a high stall converter.

http://www.summitracing.com/parts/der-13960?ibanner=MobileSwitchNo

So I guess the question is, should I go though the hassle of returning the cooler I bought and get the 13960, or will I be ok sticking with the 13950? Other than difference in thickness, they don't seem seem that different to me. And I'd prefer to not have to use the radiator cooler.