I'm trying to figure out wich tranny cooler would work best in transition with the stock one. I'm not sure if I need a 1/2" fitting or not, or is the 14,400 btu B&M cooler enough? I just want to make sure that my tranny is plenty cool when I'm pulling my Travel Trailer about 5500lbs. I have the 04 5.3l. Does anyone else have this one with an aftermarket cooler??