With transmission coolers there are different styles. The Derale Series 8000 Plate-Fin Transmission Cooler Kit w/Barb Inlets, part # D13503, you referenced is a plate and fin cooler and actually performs differently than a tube and fin style cooler. I have attached a FAQ article that explains the difference in transmission coolers and how they work. I have also linked you to a product review video for this cooler.
A plate and fin cooler is more efficient because it causes the fluid to... view full answer...