Charlie207
Full Access Member
K5L is the top end cooling system that includes 700w fan motors instead of the usual 500w, which makes it better for pulling a heavy trailer in hot weather, etc. Not all towing packages come with the K5L. For example, my 2012 XL Denali has the trailering package so it has the integrated brake controller and both engine oil and transmission fluid coolers, but it doesn't have the K5L package so it didn't come with the 700w fans.
Here is my build sheet, are there any other goodies I should be aware of?