Did all the 2007 gmc sierra 1500's come with a transmission cooler?

i'm looking at a 2007 sierra 1500 reg cab 4x4 with a standard box. has the 4.8l v8 and a 4 speed auto tranny. just wondering if they all came with transmission coolers or not? I plan on pulling a boat thru the hills so i would prefer to have one just for the tranny to maintain some longevity