Quote Originally Posted by Mamba334 View Post
Do I NEED to install an external trans cooler??
If I was going to haul it very far or very often, at highway speeds or on highways with long/steep hills .... yeah, I probably would.

I did just that, on a previous V6 Blazer ... pulling a 15.5' fiberglass boat w/70hp Yammy. My Tundra has "tow pkg" built in, and the "cooler" is part of the setup. And that's on a 4.7L V8 motor.